While I'm pretty comfortable with basic shell commands, I like the convenience of features like syntax highlighting. Lately I've discovered a few replacements for common shell commands that add an extra bit of colour:

bat: cat with syntax highlighting

bat is a drop-in replacement for cat that adds syntax highlighting and line numbers by default - great for when you want to check the contents of a script:

On Mac you can install it via Homebrew:

brew install bat

exa: ls with syntax highlighting

On a (very) similar note, exa is a drop-in replacement for ls that adds a bit more colour. By default, it just adds some colouring for different file types:

When used with options like -l it adds some colour to the structured information, e.g. the permissions:

Again, install with Homebrew:

brew install exa

ripgrep: an easier grep

I'm very bad at using grep - I can never remember whether the file or the pattern goes first. ripgrep makes grep more convenient: by default you can just give it a pattern and it will search the current folder recursively (automatically skipping hidden files and files in your .gitignore).

You get nice colourful output with the matches highlighted:

brew install ripgrep

Lots more

I've only covered tools that I've been using regularly - there are plenty more out there if you want to improve your shell. There's a long list here, and other fun tools like asciinema which lets you record gifs/videos of your shell sessions.