Yes, it's super simple. You can use a yogurt maker or apparently a thermos flask works well. I heat milk to around body temperature (stick a finger in it to test it's not too hot) mix with some ready made yogurt for the first batch - I have a yogurt maker, so use about 1 tsp per pot. I think each pot is 100 ml so 6 tsp to 600 ml milk. I also add 1 tsp skimmed milk powder to each pot for a thicker yogurt and leave it overnight.
Add 6 tsp skimmed milk powder but don't leave in the fridge. It must be at body temperature for the yogurt to act. You need to put it either in a yogurt machine or a thermos flask overnight. You could try putting it in a sealed container in an airing cupboard. The secret is to keep it at body temperature - too hot and you'll kill the bacteria, too cold and they won't reproduce to make your yogurt.
Hope this helps
I use the EasiYo yoghurt method - You can get a starter pack for £18.99 at Lakeland (see their web site) - The slimmer natural and the low fat strawberry & vanilla yoghurts are FREE......the yoghurt is made overnight and then chilled in the fridge and it's delicious....