My Emms has been on formula full time for a couple of weeks now, and this is what I do:
First thing in the morning wash all the bottles, then put 4 in the steriliser and put it in the microwave.
When Emma takes her morning nap I boil the kettle and then make up 4 bottles, quick cool them by putting in a bowl of cold water and then put in the fridge.
Bottles are then heated when she needs them.
In the afternoon I will sterilise and make up 3 more bottles in the same way for the dream feed, middle of the night, and morning feeds.
It's a bit daunting when you are used to just whipping a boob out, but once you get into a routine it's fine! I think Emma feeds little and often compared to other FF babies, but this is probably because she was breastfed. At the moment I am making 7 6oz bottles a day, she drinks anything between 4 and 5 1/2 oz during a feed.