Easiest time crushing a Vayne? Personally, Jhin is my go to. I main him but before that I always went to him as my first point because while she can dodge some of your abilities easily, simply laning against her and bullying her with your massive basic attacks can easily push her out or get a kill.
As always, stick with your support, ward, _buy a pink (especially important once you hit 6, it's such a big deal to completely counter her ult. Hang on to it and when she ults, bam, countered a large part of it.) _
For fighting Vayne with Jhin:
-Stick with your support all throughout laning phase and just bully her so hard she dies or is edged out of farm
-Try and go for kills using Dancing Grenade (Q) and basics, but using your Curtain Call (R) and using Deadly Flourish (W) will result in frustration because like I said, she can dodge those skillshots very easily.
-Don't 1v1 her, your damage per shot is insanely higher than hers but your damage per second is too low to fight her. Reloading in a fight or getting condemned will just result in a death.