It can't be over-emphasized how important it is to wrap expansions, such as $myvar, ${myvar[1]}, and ${myvar##*/}, in double quotes. Failing to do this will lead to bugs down the line when values contain characters that have special meaning to Bash, especially spaces. This is a common problem with code that has been cut and pasted from old documentation, or from bad advice posted on websites or in chat channels.
It only takes a few examples to realize how dangerous a failure to quote properly can be, especially in circumstances where files can be created by other users, and hence might include shell metacharacters. A file named *, for example, is legal, and if expanded incorrectly, can wreak havoc on your scripts:
$ cd ~/important $ myfilename='*' $ echo $myfilename important-document passwords-DO-NOT-DELETE anniversary-plans $ echo "$myfilename...
