For those in the early stages of scroll sawing there is so much to learn that learning things the hard way can be discouraging. Those of us who have been scrolling for a while have learned some things that may prevent frustration and do-overs for those who are new to scrolling. I'll start with a couple:
1. When working with lumber (as opposed to Baltic birch plywood) inspect the face of your lumber carefully before applying patterns. Imperfections are far easier to correct before you complete your scrolling. Sanding a finished piece is risky.
2. Do not let the blade lift the scrap out of your work piece. Nine times out of ten it will be fine but the blade may grab and twist the scrap causing a delicate detail to break. By the way, Murphy's law dictates that the piece that broke off will ALWAYS find the vacuum with an audible clicking sound as it goes...
3. Those tiny drills we use to drill pilot holes DO NOT like to be rushed. If you are really unlucky the tip will break off inside the work piece. Start the hole and back the drill out to clear the flutes before drilling all the way through.