Have you read the ingredients list on a low fat yoghurt? What about the ones made specifically for babies? Instead of just milk, yoghurt cultures or some fruit you have like 20 ingredients including sugar or sweeteners and preservatives.
Buying plain yoghurt is therefore best but it can be bland (and expensive!). I sometimes make my own using a small pot of double thick full cream yoghurt and a little fresh milk in a cheap yoghurt maker from Yuppiechef. It really is that simple. I don't buy yoghurt starters I just use some bought yoghurt.
To flavour the yoghurt I use fruit and honey. I sometimes make a compote from fresh or frozen berries and drain the yoghurt to get the "Greek" consistency. But if you have sweet and juicy strawberries then why not try this: dice 2 strawberries and add to 150ml plain yoghurt. Dice 1 orange segment and add to the yoghurt. Drizzle with 1/2 tsp honey (yes that is all that is needed!) and mix well. Regridgerate overnight and enjoy naturally pink and flavoured yoghurt for breakfast!