Hi folks,
Long time lurker, first time poster. Recently passed stage 2 so thought I'd offer a couple of tips from my experience.
I'd say the most important thing to bear in mind with the aptitude tests is that they are designed to break everyone, you may feel like you are failing even if you are doing well. I thought I had thoroughly screwed up in parts of FEAST yet still passed. Do not panic if you feel its starting to look dire.
Without giving away any unfair advantage, the motivation paper is pretty simple if you put some time into studying the booklet. I probably spent about 10 hours in total learning it and I felt confident answering all but one question on the test.