Even when I have a preset for cutting a material, I usually run a test cut on it before I run the full job. Nothing is worse than taking the material out of the laser and finding that it didn’t cut all the way through. I create a small circle or square (about 1/4″ or 1/2″ wide) and cut it out in a corner or on some scrap material. Then I can see if I need to increase or decrease the power before I run the final cut.
Bonus Tip: For acrylics, leave protective coverings on during the cutting process to protect the edges of the acrylic. For wood, making your cuts with more than one pass may prevent the wood from edge burning. Have some fine sandpaper handy to remove burns or vaporized oils on raw wood. Keeping your materials flat in the laser results in successful cuts.