I make a Greek like yogurt and love it.
To make 1 quart of yogurt, I use 1 quart of milk and 1 cup non instant powdered milk. I use non instant powdered milk that I purchased in bulk. Not sure you can find it at the grocery store. My starter of choice is Stoney Field.
I incubate in the oven with an oven light on. Through trial and error, I found that if I switch out the oven appliance light bulb to a 75 watt household bulb, the temp stays perfect. I use a large 2 quart glass measuring cup covered with saran wrap and leave the mixture in the oven for approx 12 hours....the results are a wonderful tangy flavor.