Truly, such a little tip that really has made a difference to my homemade yogurt: don't stir the yogurt starter into the warm milk. Don't stir! Just pour the warm milk over the yogurt and let it incubate.
I can't recall where I picked this method up or even if it was promised as a tip, but I like it because my yogurt has a sweeter, milder flavor and a lovely jell. Plus, it's one less step!
Maybe I should just give you the run-down for how I currently make yogurt? It's a little different from my 2010 instructional post and subsequent posts (using glass jars, wild starter).
1. Plug in yogurt incubator to warm up with glass jars in it.
2. Use another glass half-pint to measure the (pasteurized) milk into a saucepan.
3. Heat the milk to 180F using a candy thermometer to check.
4. Set aside milk in its pan to cool to 100-110F.
5. When milk has cooled to that temperature range, dollop a teaspoon-ful of plain yogurt from the last batch of yogurt into the bottom of each glass jar in the yogurt incubator. I don't measure precisely!
6. Pour the milk into the jars.
7. Don't stir!!
8. Loose cover.
9. Incubate for 1-2 hours until jelled.
10. Refrigerate, making sure to put the "Belgian yogurt - save this starter" label on one of the new jar lids.
More fun to look at Granny and Phoebe than it is to look at cups of white stuff which don't change their looks over the years, unlike these cuties.