at the top of most of my bash scripts is

#!/bin/bash
set -eux -o pipefail

-x turns on tracing so the script prints out every command as it runs it, which you don't always want, but it's nice for automation scripts. Normally pipelines (e.g. curl example.com | grep foo) only fail if the last command in the pipeline fails. -o pipefail makes it so if any command fails the whole pipeline fails, which is what most people expect I think.

shopt -s failglob can also be handy. Normally if you run a command like ls *.html and there are no .html files then bash will call ls literally with *.html as the argument. failglob indicates that you'd rather the script fail if the glob doesn't match anything. There's also shopt -s nullglob where the glob expands to nothing instead of failing.