I combi fed my first.
I will get onto tips and tricks, but full disclosure, I hated it. I much preferred exclusively breastfeeding. I'll go into details on why later.
In terms of tips. The main one is to establish breastfeeding first. This will take a few weeks (around 6) and will involved cluster feeding and feeding on demand. It's worth looking up the fourth trimester in advance so you know what cluster feeding looks like and what it isn't (baby not getting enough)
We used pre made formula in pre sterilised bottles at first with my son. A good start if you don't want to express. My son is actually allergic to milk so it wasn't a good idea for us, but that isn't universal.
He never had any issue with swapping from breast to bottle. We pace fed bottles and I recommend you look this up too. We never changed teet sizes either. Your boob holes don't get bigger so no reason to make bottle holes bigger.
By 16 weeks we fully went to combi feeding and we replaced 2 feeds a day with special formula. These feeds were at 10 and 3. We avoided a bedtime bottle because of my son's issues with reflux and allergies, issues he didn't have when fed from the breast.
By 7 months (we weaned early due to his issues) he was on 3 meals a day and had dropped his lunch time breastfeed. That meant I was only breastfeeding morning, evening and overnight.
So, here's why I hated it. It's soooooooo much more work that breastfeeding. Once breastfeeding is established, whipping the boob out is a lot easier than sterilising bottles, making up formula or expressing and then expressing missed feeds. It actually made more work for me. In an average week of 14 bottle feeds, husband could only do 4 (the weekends) so it didn't give me a break at all. The special formula we used didn't come pre made so I had to faff around with kettles and powder. If we went out I had to remember all that kit.
My sons issues meant that any cows milk based product that went in, came out again in a stinking mess.
My youngest was exclusively breastfed and it was a much nicer experience. Even though we tried her with a bottle at the same time we introduced one to my eldest, she refused point blank. Whether a breastfed baby takes a bottle is a matter of chance. I don't think it has anything to do with when you introduce it.
My husband has never fed her, but he was still able to help and give me a break. He did that by taking care of the house and toddler, he'd hold her, wind her, change her. He'd take her for walks to let me sleep. To be honest all that was more helpful than the faff of making a bottle. At Christmas, your partner can be on hosting duties, cooking duties etc, also depending on how birth went you might not be up for much on the day anyway.
I hope this is useful. Combi feeding can work, but from my experience it isn't the 'best of both worlds' that it's sometimes presented as.