I failed last October and signed up immediately, the day I found out, for the April Exam which I passed. MDM for both. Here is what I did differently:
1. Started studying that day (when I got my results) with the goal of hitting 300 hours total before the test. (I was mostlikely at 300 to 350 but I stopped counting in February)
2. I purchased several new practice problem books, and then worked through them all.
3. I read textbooks. 1.5 hours everyday (Taking the light rail) plus 2 to 3 hours of problems.
4. I tabbed as I went along.
5. I focused on 4 resources (MERM, Mechanical design book, materials book, and machinist handbook) so that I could navigate it with out much effort. I brought about 10 books in total, but only if the others had a table I thought I needed. During the test, I only opened books I focused on.
6. I made notes of what I needed to brush up on, tables I used and stuff I needed to go back to before the test and then went back to it the weeks leading up to the test.
7. I took a day off occasionally.
Really, when I received my diagnostic I took an honest look at my study habits before the failed test and determined that I tried to get away with doing the bare minimum of effort. I spent so much time studying the second time around that by the end I couldn't come up with something I needed to look at. It is safe to say I was burnt out. I think doing it again was the way to go. It can be done! Hope this helps!