Actually foolproof? (Well, consistent assuming you're not actually a fool?) Sorry if this sounds jerky:
Get a professional chocolate book, like the one from the Culinary Institute of America. Read the whole section on tempering. You aren't going to use the more complex techniques, but it helps to understand them and the overall tempering process.
Get real couverture chocolate, ideally in pistoles (or you can chop bigger chunks). You can't reliable temper stuff like Nestle chips because they have a ton of emulsifiers and the like. If you're learning and/or need to do it reliably, only use high quality "professional" chocolate. (I've had consistently good results with Valhrona and Barry Callebaut couverture pistoles. Guittard also has couverture.) This isn't meant as snobbishness, it's just that couverture chocolate is meant to be tempered, and most other chocolate has additives to make it do other stuff (which I have no objection to!)
Get quick reading digital thermometers. Ideally both an infra-red and a probe thermometer. You're going to be learning how the chocolate heats up and cools off and you need to be pretty precise (within a couple of degrees F or a degree C), so you need good tools. Though you can make it work with one or the other.
Follow the process in the book that uses the microwave and seeds the melted chocolate. I'm not going to spell it all out here, plus the exact temperatures vary depending on the type of chocolate you're using, so you really need a complete reference.
Go slow. Use short bursts in the microwave and stir/check temp repeatedly so you sneak up on the temperatures without overshooting. Don't try to do this with only a tiny bit of chocolate (like 50 or 100g) also, don't try to work with 2kg your first time. Having a decent amount of mass of chocolate (500g? 800g?) makes it easier to not overshoot.
I know I sound like a snob+jerk, but it's a somewhat tricky process and learning it on your own is much, much easier when you "do it right."