I will probably try to exclusively bf first 6 weeks but with my first I started combi-feeding a little before that. A couple important things are if you are combi-feeding earlier/from the start, be consistent about what times you are doing bottles so that your supply can establish properly. Also look up paced feeding, a way of bottle feeding so baby doesn't end up preferring bottles to boob because it is easier. It is best to exclusively bf first 6 weeks so your supply is properly established but as I said, I did it a little earlier than that. I combi-fed a bottle a day generally in the evening, but it gave good flexibility. If you are away from baby a time you would usually feed you'll need to pump to maintain supply. If a short period you can probably just feed as soon as you get back. I combi-fed for about a year and plan to do it again this time.
@Abi thank you will give it a listen x