I used Allen for 1&2 and Schweser for 3 (Secret Sauce is awesome). All of them were pretty basic in their coverage and wide of the mark in many areas. My strategy, which worked for passing all 3 levels the first try and finishing within the 3 years was the following.
1. Read *ALL* of the CFA materials. Write copious amounts of notes, create notecards from key formulas and points. Starting ~6months ahead of the exam.
2. Complete some of the practice problems in the back of the chapters, but not much.
3. About 2 months before the exam, take practice tests constantly with the Schweser exam software (I liked that better than Allen). Timed and untimed. Score yourself with the built-in tools.
4. Hammer weak areas found through testing. Re-read chapters and sections as needed and hit those areas with notecards.
5. 2-weeks before the exam take more practice tests, find whether key areas have been addressed, if not, address those plus the more broad areas.
6. the last few days take off of work and hammer notecards, notes, and take a few broad practice exams (timed).
Do NOTHING the night before and morning of the exam. I always went out for dinner, had a beer or two to relax, and went to bed early.
The biggest reason why people fail those exams is that they do not prepare. They panic when they are constrained by time and when they face multiple choices for complex problems. Be concious of time throughout the session and leave yourself time at the end of each session. Skip answers that are taking too much time.
DO NOT change your answers at the end and above all else, when in doubt, the answer is *ALWAYS* "C".
a good place to visit for exam prep is
www.analystforum.com