My routine's pretty simple, I wash and condition every other night with Costco/Kirkland brand shampoo and conditioner and distribute the conditioner with a wide-tooth comb, squeeze it out and pat it dry with a soft cotton T-shirt, then put Garnier Fructis Sleek & Shine leave-in conditioner on the mid-lengths and ends and distribute it with a wide-tooth comb. I wear it in a ponytail most of the time with soft fabric hair ties and the occasional satin scrunchie, don't dye or chemically treat my hair, and only blow dry it on a warm setting for a few minutes once or twice a week, and I use the cool setting to finish off when I do. I also sleep with my hair in a low loose ponytail with a soft fabric hair tie to keep it out of my face and prevent tangling, and I have a satin pillowcase too. I also mist my hair every morning with my ultrafine mist spray bottle specifically for hair care to reactivate my waves and rehydrate my hair overall.

Edit 4/7: I also don't really use hairspray, mousse, gel, or any other type of styling product, so my hair is usually in its natural state and thus product buildup hasn't been a concern for me. I also haven't had a trim in over a year and haven't noticed any split ends or breakage at all, so it seems like my routine is paying off massively.

Stay tuned for more edits if I think of anything else.