[jnem]

I use JetBrains Webstorm, and on that hitting CMD+SHFT+F creates a search local to the selected folder in the directory tree. Seems pretty intuitive to me, but finding files themselves, as opposed to string constants and the like, is actually the more difficult thing Ive yet to figure out.

[lmm]

Ctrl-Shift-N gets you an "open file" dialogue that does slightly fancy filtering/searching (e.g. you can put a substring of the name and it'll find it).