1. If you can buy it, don't build it2. Start small and keep on building
3. If the project is twice as large as your last, the sawdust increases four fold4. With shelves, it is not the strength of the screw
that holds up the weight, but the friction of the joint. Make sure it is flush and tight.
5. Don't forget that Kreg screws can be used without pocket holes6. It is often easier to assemble upside down
7. Build something your family likes or needs and you can keep on building
8. If you design for remote assembly/disassembly, you can build larger than door openings and take it when you move
9. With new wood, start with the lowest torque setting on your drill. Keep going up until the joint has no gap/is flush.
10. Be careful with softwood - if you miss the pocket hole, the screw will still go through, but will break the surface on the other side