TX I thought your first bunch looked pretty good. These look even better

Nice work! That bitz is nice ain't it!
Oh, as a measuring device...this I might could pass along something useful on...
What I did was figure out how much I wanted painted. With Blazer vanes, I think 6" is about right. Then, I measured where the feathers start off my Bitz, which is 5/8" from the inside (low point) of the nock. Then I take a 6" piece of paper about the size of a dollar bill and mark off where I want my colors to be. I also mark where my feather (vane) will start and end. Since its just a piece of paper, if I get paint all over it...no loss...in fact, it keeps me from painted my crester. It also allows me to be pretty consistant.
As far as brushes, my girl happens to be an artist, so she got me some white nylon brushes of various sizes. Think she went to Michael's, they have yellow handles, but I'm on the road so I can't look at who they are made by. They have held up well.