These are some random notes about my emacs configuration, as it may be useful to others.

I keep my usual configuration under ~/.emacs.d/ with init.el being the entry point.

I find it useful to bring up the debugger if I hit an error as the trace usually has enough information to figure out what's going on: 

;; makes it easier to handle startup errors
(setq debug-on-error t)
;; makes it easier to handle freeze errors (if you then SIGHUP or SIGTERM emacs)
(setq debug-on-quit t)

Because I use a different computer for work and personal purposes ("don't cross the streams") I have a simple macro that lets me load config sections depending on which machine I'm on: 

;; allow customizations per machine
(setq hostname (car (split-string system-name "\\.")))

(defmacro execute-on-machine (machine-name &rest body)
  "Execute BODY only if the machine name matches MACHINE-NAME."
  `(let ((current-machine hostname))
     (when (string-equal current-machine ,machine-name)
       ,@body)))

(setq work-machine "mellotron")
(setq personal-machine "moog")

For example, I can work with a different set of agenda files for org mode depending on whether I'm having professional or personal fun: 

(execute-on-machine work-machine (setq my-custom-org-agenda-files ('"the" "list" "of" "files")))

(execute-on-machine personal-machine (setq my-custom-org-agenda-files '("~/Documents/org-mode/journal.org" "~/Documents/org-mode/Professional_Development.org" "~/Documents/org-mode/Notes.org" "~/Documents/org-mode/Community.org" "~/Documents/org-mode/Reference.org" "~/Documents/org-mode/Todo.org" "~/Documents/org-mode/Bookmarks.org")))

This snippet lets me share the config between multiple machines and not have startup errors if I: 

;; this should happen after (package-initialize)
(setq package-list '(ace-jump-mode aws-snippets awscli-capf calfw company-tabnine csound-mode darkroom dtrt-indent ein eproject evil evil-mc evil-visual-replace gnutls helm-tramp ipcalc imenu-list kubed minimap neotree ob-go ob-async ob-sagemath org-download org-mru-clock org-notify ox-jira popup rtags shell-pop sqlite3 emacsql-sqlite3 unicode-fonts with-simulated-input workgroups2 yaml-mode yasnippet polymode poly-org ob-sagemath))

(dolist (package package-list)
  (unless (package-installed-p package)
    (package-refresh-contents)
    (package-install package)))

With this, any missing but required package will be installed (provided I don't forget to add it to the list).

This takes care of loading any other .el files on ~/.emacs.d/: 

(defun load-directory (dir)
  "Load all Emacs Lisp files in a directory, excluding init.el and files that start with .#."
  (let ((load-file-silent t))
    (dolist (file (directory-files dir t "\\.el$"))
      (unless (or (string= (file-name-nondirectory file) "init.el")
                  (string-prefix-p ".#" (file-name-nondirectory file)))
        (load file)))))

It avoids loading init.el, which would cause an infinite loop, and any file-is-being-edited markers. Also, because it only targets .el files, I can simply rename the extension of a file if I want to avoid loading it. This comes in handy when dealing with startup issues (usually after an upgrade).

What comes next is taken from https://github.com/LionyxML/emacs-solo/blob/main/init.el: 

(add-to-list 'save-some-buffers-action-alist
             (list "d"
                   (lambda (buffer) (diff-buffer-with-file (buffer-file-name buffer)))
                   "show diff between the buffer and its file"))

When you're quitting emacs with unsaved work, you get asked what you want to do with each file. This adds the very useful option of showing us a diff (so we can answer intelligently).

I then just call load-directory: 

(load-directory "~/.emacs.d/")

I use hydras a lot to avoid having to remember lots of shortcuts, and because I frequently change shortcuts depending on what I'm working on. A trick I use for discoverability is to have a meta hydra that calls all the other ones, and I wrote it so that it adds additional shortcuts depending on the context from which it's called: 

(defun hydra-meta-context-aware ()
  "Context-aware version of the meta hydra showing relevant options based on current context."
  (interactive)
  
  ;; Detect various contexts
  (let* ((is-on-url (thing-at-point 'url))
         (is-on-email (thing-at-point 'email))
         (is-on-filename (thing-at-point 'filename))
         (is-in-org-mode (derived-mode-p 'org-mode))
         (is-in-prog-mode (derived-mode-p 'prog-mode))
         (has-region (use-region-p))
         (is-in-dired (derived-mode-p 'dired-mode))
         (is-in-magit (derived-mode-p 'magit-mode))
         
         ;; Start with your existing hydra heads
         (hydra-heads
          `(("q" nil "quit")
            ("se" hydra-searches/body "Searching")
            ("sh" hydra-shells/body "Shells")
            ("u" hydra-kill-ring/body "Kill Ring")
            ("h" hydra-helm-org-rifle/body "Helm")
            ("sp" hydra-spelling/body "Spelling")
            ("p" hydra-profiler/body "Profiler")
            ("l" hydra-org-links/body "Links")
            ("e" hydra-eval/body "Eval")
            ("x" hydra-org-export/body "Export")
            ("z" hydra-org-misc/body "Org Misc")
            ("k" hydra-epa/body "Encryption")
            ("K" kubed-transient)
            ("v" hydra-visibility/body "Visibility")
            ("m" hydra-multiple-cursors/body "Multiple cursors and rectangles")
            ("b" hydra-org-babel/body "Babel")
            ("f" hydra-focus/body "Focus")
            ("t" hydra-treemacs/body)
            ("g" hydra-emacs/body "Emacs")
            ("d" hydra-describe/body "Describe and help")
            ("D" hydra-db/body "Databases")
            ("w" hydra-workgroups/body "Workgroups")))
         
         ;; Prepare a list for context-specific suggestions
         (context-heads '()))
    
    ;; Add context-specific heads
    (when is-on-url
      (push '("U" browse-url-at-point "Open URL at point") context-heads))
    
    (when is-on-email
      (push '("E" (lambda () (interactive) (compose-mail (thing-at-point 'email))) "Email address at point") context-heads))
    
    (when is-on-filename
      (push '("F" find-file-at-point "Open file at point") context-heads))
    
    (when is-in-org-mode
      (push '("T" org-todo "Toggle TODO") context-heads)
      (push '("S" org-schedule "Schedule") context-heads)
      (push '("L" org-insert-link "Insert link") context-heads))
    
    (when is-in-prog-mode
      (push '("C" comment-dwim "Comment") context-heads)
      (push '("D" xref-find-definitions "Find Definition") context-heads))
    
    (when has-region
      (push '("W" kill-ring-save "Copy region") context-heads)
      (push '("K" kill-region "Cut region") context-heads))
    
    (when is-in-dired
      (push '("R" dired-do-rename "Rename") context-heads)
      (push '("M" dired-do-chmod "Change mode") context-heads))
    
    (when is-in-magit
      (push '("G" magit-refresh "Refresh") context-heads)
      (push '("P" magit-push "Push") context-heads))
    
    ;; Create and call the hydra with combined heads and context suggestions
    (eval
     `(defhydra hydra-meta-dynamic (:hint none :exit t)
        ,(format "
The Meta Hydra, which lets you jump into any other Hydra
_q_ Quit
_se_ SEarching          _e_ Eval
_sh_ SHells             _x_ eXport
_sp_ SPelling           _v_ Visibility
_u_ Kill Ring           _l_ Org Links
_w_ Workgroups          _b_ Org Babel
_p_ Profiler            _f_ Org Focus
_k_ encryption          _z_ Org Misc
_d_ Describe and help   _h_ Helm
_D_ DB                  _t_ Treemacs
_K_ Kubed
_m_ Multiple cursors and rectangles
_g_ Gnu emacs

%s
"
                (if context-heads
                    (concat "Context-specific actions:\n"
                            (mapconcat (lambda (head) 
                                         (format "_%s_ %s" (car head) (nth 2 head))) 
                                       (reverse context-heads) "  "))
                    ""))
                
        ;; Combine your standard heads with the context-specific ones
        ,@hydra-heads
        ,@context-heads))
    (hydra-meta-dynamic/body)))

;; Replace your current binding or add a new one
(global-set-key (kbd "H-h") 'hydra-meta-context-aware)

H stands for Hyper key in that global binding, and I have that bound to right control: 

(setq ns-right-control-modifier 'hyper)

To avoid finger strain (depending on which hyper key I want to use) I can also use the left control as a right control thanks to my Model 100, which lets me change the mappings based on layers.

Having a programmable keyboard is very useful for shortcuts, because you can create arbitrarily long prefixes and then just bind them to a special key. For example, here's my Github Copilot config, including its corresponding key binding: 

(progn
  (require 'copilot)
  (add-hook 'prog-mode-hook 'copilot-mode)
  (add-hook 'git-commit-mode-hook 'copilot-mode)
  (add-hook 'org-mode-hook 'copilot-mode)
  (define-key copilot-completion-map (kbd "y") 'copilot-accept-completion)
  (define-key copilot-completion-map (kbd "n") 'copilot-next-completion)
  (define-key copilot-completion-map (kbd "c") 'copilot-clear-overlay)
  (global-set-key (kbd "C-M-S-s-u") 'copilot-complete)
  )

C-M-S-s- is quite the prefix, but for me, it's just the any key (that means a key labeled "any"), so to trigger copilot completion I just do any-u. The main benefit of a long prefix (that you can get with just one key press) is that you don't collide with other prefixes on the system.