I wanna wig out

I started wearing wigs a couple years back and after a few months I stopped because I noticed that every single time I put on a wig it would always do this annoying bunched up thing at the top center of my head and make the wig look funny. I can never find a solution, so I just stopped. I want to start wearing waves again because it's fun and creative plus it's an easy way to save time on prepping for work in the morning. If anyone knows why the wigs kept doing that and how I can avoid it, I'm all ears. Also my hands suck so I would like to know the easiest cornrow braid down style for under the cap. I have thick af natural 4b hair and it's not short enough to fit under most caps loosely. And how often should I take it out, wash my hair/scalp and redo my braids?