What is the best way to highlight weft hair extensions?

My extensions are 100% human hair in weft form. I usually cut them to the width I want and sew the clips on myself. I would like to highlight them and I've done it before but it seemed like it was really time consuming and hard. I'm just wondering if anyone has any tips/tricks that would help me out. No, I don't want to take them to a salon. Thanks :)