I've been wanting to make my own yogurt for awhile. Partly because it's fun and easy, and partly because it's cheaper than buying it and when you make it you can avoid accumulating all those pesky yogurt containers. At least where I was living last, they were not recyclable. I just bought a glass bottle of milk (the kind you can return for a bottle deposit) and a glass yogurt container to use for my starter and to refill with my next batch.
My first attempt at making yogurt was semi-successful. The milk thickened into what looked like yogurt, and the final product was edible, but it lacked the distinctive tang of any yogurt I've ever had.
A couple of possible reasons for this:
I used whole milk instead of reduced fat.
I used a starter culture from a quart of yogurt that had been open for a few days. Maybe the culture wasn't fresh enough.
The process is relatively easy. You take the milk, heat it up to 180 F, and then let it cool to a temperature conducive to yogurt-growing (90 F or so). Then you add 2T of starter for every 2C of milk, stir to incorporate, and place in a jar. Then put the jar in a cooler full of hot water, and leave it undisturbed for 3-6 hours. Then put it in the fridge, and leave it overnight before you eat it (that keeps other organisms from setting up camp before the yogurt is cooled).