I don't use a yogurt maker.
3,000 years ago folks didn't have electric yogurt makers, and they made yogurt just fine....
Heat a pan full of milk to simmer. Turn the heat off. When you can leave a finger in the milk for 10 seconds without pain, add your starter. (about 1/2 cup or so of plain yogurt) Stir it in. Wrap the lidded pan of milk and starter in a big warm towel and leave overnight. (if you have a gas stove with a pilot light, leave it in the oven to be kept warm by the pilot light)
If it's still runny in the morning, either it needs to sit longer or it needs to be kept a bit warmer. Either one will solve the problem. (or you can cheat by adding a lot of starter)
When you are happy with the consistency, put it in the fridge.
To make cheese, dump the yogurt into a "bag" made of cheesecloth, set it on a slanted board, and put a pan of water on top as a weight. Leave it for a day where it can drain without making a mess.
Salt the resulting soft cheese as you like. Add sage, pepper, or other herbs as desired.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson