1. Screenshot Shortcut

The default when taking a screenshot is to save it, but most often we want to just send it to someone right away so to make things easier, change the shortcut to:
⌘ Cmd + ⇧ Shift + 4

Go to System Preferences -> Keyboard -> Shortcuts tab

2. Speed of Mouse Cursor

The default speed is too slow in my opinion, change it to your liking, he is mine 🙂

Go to System Preferences -> Mouse

3. Speed of keyboard Cursor

The default here is also slower than what I prefer.

Go to System Preferences -> Keyboard

4. Untick the fn Option

This option will remove the need for pressing the fn key with one of the F1, F2, F3.... keys.

Most often I use the F2 key to change variable names in VsCode.

Unfortunately, this only works for an apple keyboard, not external ones.

Go to System Preferences -> Keyboard

5. Text Replacements

Save time by putting your most frequently used phrases here.
My favorite is the email one :)

Go to System Preferences -> Keyboard -> Text