I started rehairing with the needle and thread method. I just recently made my own tool with and xacto handle and needle. I havent tried it yet though.
I love rehairing as its relaxing for me, kinda like crocheting.
I try to get as close as possible on repairs as to keep the value but sometimes if its one of my ponies ( Ember with lavender hair missing plugs) I found a fakie that was super close and donated.
I do full heads, tails and repairs when needed. My first one ever was my childhood Fizzer whom had gotten a mohawk and bobtail from my sister.
The needle/floss method is super easy. U will want a set of pliers, a thimble and a pair of $ store garden gloves. I just use the right. Floss can majorky cut ur fingers in not.