Always put a couple layers of tape under the things you use to draw lines. This will hold your strait edge or template above the finished surface. This is important because if it is touching the ink will run under the edge and make a mess. Put at least one coat of clear on the surface you want to ink, if you do this you will be able to use rubbing alcohol to wipe off mistakes. I like to have enough clear to wet sand (so a couple good coats) this will help the ink flow out smoothly. Prep the surface, It must be very clean. When you finish an area and you are happy with it, seal it in a light coat of clear to protect it. This will allow you to erase mistakes from other areas without hurting the good one. Let clear dry!!!
Hope this helps I will type more later.
Derek