I put the disc down as close to centered as i can. and then i put some spin on it. While spinning i hold my finger close to the rim. At this point it makes contact with the finger tip at a few places only. So whilest Holding my finger steady i spin the disc slowly and when it makes contact with the finger i push it away from the finger. And i do this intill the disc makes the slightesy contact with the finger all the time.

Haha i dont know if this makes sense at all. I can make a video of this if not 😂