Train your baby early to be a less fussy sleeper
There are a few simple things you can do to optimize your baby's sleep environment, of course: keeping the room cool, using baby sheets that stay cooler during hot summers, and figuring out exactly how your little one prefers to be swaddled. However, a major way you can benefit your baby and yourself is to train your baby to self-soothe and be less fussy about sleep conditions. Establish a consistent, calming sleep routine to get your baby drowsy before laying them down. Ease into letting them fall asleep on their own. If they are used to self-soothing, they won't expect to be rocked and coddled every time they momentarily wake up during the night, taking some stress off of them and you.
Plan for easier diaper changing
Does a diaper change totally wake your baby up? Plan ahead to put off diaper changes as long as possible while still keeping your baby comfortable. Use heavy-duty nighttime diapers and pre-bedtime diaper cream. If you absolutely must change their diaper, i.e. if they're about to leak onto their crib sheets or they have a bowel movement, then be extra gentle, quiet, and use warm wipes and cream to keep the baby drowsy enough to go back down to sleep easily.
Prepare ahead of time for midnight messes
Sheets for babies, especially newborn sheets, take a beating. There's spit-up, drool, boogers, vomit, diaper blowout or leakage ... all the unpleasant icky wet stuff that can irritate your baby's skin or wake them up in the middle of the night. Be prepared with waterproof bedsheets to make cleanup easier. Keep a second set of baby sheets ready nearby to get the bed re-made and baby back to dreamland ASAP. Some parents suggest putting a fitted sheet on both sides of the mattress so you can flip it quickly and not sleepily wrestle with a stubborn sheet.