I've only been a CFI for a year, but this is what I think.
Just do this:
1). Buy a CFI PTS ($10)
2). Read and highlight the relevant sections of the AIH, AFH, PHAK, AC61-65 and FARs for each section of the PTS (free)
3). Make study guides/notes on the above and know the heck out of that material (free)
4). Practice teaching the sections of the PTS. Teach the cat, dog, wife, goldfish, whoever. Just get used to organizing your thoughts and hearing yourself talk and navigating through the material so you know it solid (free)
5). While practice-teaching the sections in the PTS, buy the Sheppard Air CFI bundle ($100). It gives you all the info and study questions for the written tests on your computer or iPad.
6). Take and pass the FIA and FOI written tests ($150 each). If you did Shepard air, you will pass, because the material will be coming out of your ears
7). Find a local FBO and a flight instructor to get a spin endorsement in a 172 (2 hr flight = $350)
8). Go through the maneuvers in the PTS in a complex plane that you will use for your checkride, with your flight instructor sitting in the left seat and you in the right seat. It is weird at first but you get used to it. Talk while you fly. Explain what you are doing throughout the maneuver. Your instructor might pretend to be a student while you critique his mistakes. Do this for all the maneuvers until you're comfortable teaching them. It doesn't take long, because nothing here is new (6 hrs max = $1400)
9). Go over study material again with your CFI (4 hrs ground = $200). Know everything about your checkride airplane's systems and resolve any questions. Study the POH (free) or buy a generic POH for your plane ($60).
10). Take the checkride with the FSDO (free). Don't be upset when told you didn't pass... It's the FAA way. Spend an hour retraining with your CFI ($225) and take the checkride again (guess what, it's free). If the FSDO is busy, they might send you to a DPE ($600).
Most of CFI prep is you studying and practice-teaching on your own. If you have a question, ask people on the forum, then ask for a reference and look it up to make sure they gave you the right answer. You don't need fancy frill-filled tie and epaulet-wearing instructors at schools/academies/programs to teach you Piper Arrow Systems and Lesson Plan Organization. You know why? Because they're not going to be there when you're training your first student or 100th student. The real learning begins AFTER you pass your checkride and start training people. And it can be scary. You're on your own to get the job done, and it can be very rewarding. That's why you need to take the initiative to learn this stuff and know your resources and practice. It's a lot cheaper this way too.
