I mostly use Ctrl-TAB to cycle through the tabs I have most recently been working on. I can seem to manage a stack of 4 or 5 files without thinking in this way. If the file is out of the stack then I usually settle for reopening it again using Ctrl-O.
Or if the file I want is related to a piece of code I am looking at, so highlighting a variable, method, etc that is defined in that file and hitting F-12 works.