When I do spray can cresting, I tape off where I want the cresting to stop at after 1st sanding the shaft, then I wrap a piece of scrap paper around the part I don't want any overspray on, then I paint the shaft. Now for paint, I use rustoleum enamel. It takes 2-4 hrs to dry to the touch, which is what you want. If you get the fast drying paint, the paint does not have time to flow together before it dries, and you will be unhappy with the results.
After painting, remove the blue painters tape, and stand the shaft upright to dry for atleast 24 hrs with no disruptions. Arrow building is not something that can be rushed. Believe me, I have done it, we all have probably done it, and the results suck when you rush, so remember wait 24 hrs between doing steps. After the paint has dried, put 1 coat of clear on, then another 24 hrs later you can do your cresting, then another 24 hrs later (are you noticing a pattern) do another coat of clear coat, then again in 24 hrs do your final coat of clear.
Just my .02, and I can say that I rushed a set 3 weeks ago, and they were simply beautiful untill the stain underneath the paint blead thru after I had finished the arrows. I was told don't rush, I had never rushed untill then, and now I hope to never do it again.