Purging Cache

Sometimes it's also worth visiting the cache drive and deleting the files there.  There's times when I start to lose space due to other Adobe software (which all point to the same cache) leaving behind their temp files.

You could try to reign it in from the outset by setting the cache to the minimum amount needed. Apparently given how garbage AE's cache management is, it's not a good idea to give it too much leeway...

Mylenium

I purge any time I feel like AE is slowing down. Sometimes I will go days without having to purge. Other times, I'll do it several times when working on a single composition. It all depends on the project.