A godsend for saving time - the ab (abbreviation) command. This command lets you shorten a long sequence of characters (be it a text or a complex command) into another sequence of any length. It works in both insert mode and command mode. If you frequently edit text using a lengthy command, this feature will significantly save you time. For example: :ab ul s/\<./\u&/g to capitalize every word in a line. When you enter command mode (type :) and type ul, vim will automatically expand it to s/\<./\u&/g for you.

Additionally, the map command can save even more time, but IMO the ab command offers more control for handling various cases. In my example, you can use ul to only capitalize the lines that have a specific pattern using the global command g.

Another overlooked aspect is the .exrc file. Enabling it with set exrc in your config allows for different setups based on different situations. For instance, when writing notes, I prefer to have line breaks on to make the text look nicer on the screen. In contrast, when writing code, I don't require this option. I simply need to place set linebreak in the .exrc file in the note-writing directory to adjust accordingly.