I was emotionally abused and neglected pretty much my entire life by my mother, so I'm still learning, but a few things I can think of...

Foods. Feeding the baby, and getting a treat for you. I do things like hot chocolate or myg favorite candy now and then. Careful not to go overboard, cuz sugar can cause problems sometimes.

Baths. Bathing the baby and taking some time to just relax and take a bubble bath for you.

Naps. Kinda self explanatory. You are probably not getting much sleep right now, so napping when you can, often when the baby is down for one also, can really help.

Sometimes, mothering ourselves (self care) can really be as simple as "have I eaten, bathed and slept?" I have days that changing out of my PJ's is the best I can do, so I try to remember these simple things.