AudioVariator is a script for Unity that allows you to easily set up groups of similar sound effects to be triggered in random order (e.g. for footsteps or shooting sounds). It can also create additional subtle variation through randomized pitch shifting of the sound effect samples. Get it here!
This kind of simple functionality often gets overlooked by non-audio folks and once everybody's busy developing crucial gameplay features, audio features have a sad tendency to drop to the bottom
of the to-do lists. Big, comprehensive audio solutions for Unity like Fabric and AudioToolKit offer the same (and much more) functionality, but of course come with the corresponding * complexity
*Edit: it said price tag here, but since I made these little scripts, many audio solutions have become free for indie devs. If you're making a simple game, they might still be overkill and too much work to learn, though.. ;)