My hair is not waistlenght yet, but maybe I can help anyway

My way of dealing with tangles is to prevent them most of the time. When it's windy I wear my hair in a braid or updo, or under my coat. That really helps. But i guess you know that already.

When I do get tangles I try to finger comb my hair. I start at the bottom and work my way up, very slowly. If it's really bad I need to apply conditioner to the tangles, that helps.

When my hair is in good condition it tends to get less tangles. So once a week I apply oil (jojoba, olive oil, sweet almond oil etc) an hour or more before I shampoo and condition. That makes my hair really smooth, and easier to comb.

HTH