This really is fabulous, so very easy to use.
I bought this because I wanted to stop buying yogurt in plastic pots and also save on my shopping bills.
I use 1 litre of full fat UHT milk, with 2 tablespoons of yogurt and 2 rounded teaspoons of semi skimmed powdered milk.
Dissolve the powder in a drop of the milk first, then put it in the large yogurt container with the milk and yogurt, stir, switch on and leave it to do its stuff. Initially I left it for 10 hours, but it didn't look thick enough, so left it for another 2 hours. Looked much better and thickened more after being left in the fridge.
I add berries, flaxseed, linseed, cacao nibs, and chia seeds for a healthy breakfast or pudding, tastes delicious. 
My starter yogurt was Aldi greek 10% fat.
Now I don't have to plastic pots a week to add to the recycling and it's much cheaper to make it yourself than buy it.
Definitely recommend.