I overstudied for the FE roughly a year and a few months ago. Best advice in retrospect is to get your hands on the reference booklet, with all the equations and formulas. (a copy from your previous exam is just fine - doesn't have to be the most recent)
If you familiarize yourself with EVERYTHING in that booklet, you will be more than prepared. By familiarize I mean you should be able to look at any equation/fact/table in that book, and know what kind of problem it would show up in.
Go through that booklet item by item. If you know what something is for and how to use it, check it off and move on. If you aren't sure, be honest with yourself and mark it to look up in your own/buddies' notes/texts. When you look something up, find an example problem or two and use it to burn it back into your recent memory.
For reference I took both "general" sessions (all-around) as that matched my education in architectural engineering the best. I'd taken courses that covered most of the material on a basic level. There were a few subjects I had zero-to-little experience in (programming diagrams/environmental engineering...), and quite a few more "weak subjects" (chemistry/economics), but after going through once to nail the easy/solveable problems, coming back to the tricky stuff I was able to get an answer for probably 80% of the questions I gave a pass on the first go-around.
Those tricky problems all came down to recognizing a concept/formula that was in the booklet and knowing it was there to look up.
BIG SUGGESTION: retake the test at your next opportunity. the stuff you've been studying and the advantage you have now from taking the test once will sieve quickly from your memory and you don't want to put your re-take off.
