Hair masks: personally i switch from using whichever from the brand Shea Moisture. but i’ve heard aztec clay is great for curls as well (i’ll be trying it soon so i’ll try to update you guys). But if you don’t have the budget for those making you’re own is great to. commonly used ingredients are; eggs, mayonnaise (trust me it helps), conditioner (to fill it out), aloe, and oils. but you should do more research for what you want for your hair so you can add whatever you need. i usually leave my hair masks in for as long as i can but some masks require a specific time, if you make your own you can keep it in for however long you like but preferably over 45 minutes.
This next thing isn’t really a “hair mask” but it’s great for chemically damaged hair or heat damaged hair. get a protein treatment they work wonders for restoration for curls. :)