Like anything you do whether you be a carpenter, a mechanic, or a Brick Mason like me, there alot of tools that you can buy to make your job easier, but not all are nessasary. Building airplanes is the same. There is a tool for about everything, but not all of them are nessasary. Here are a few building tools and supplies that I would classify as nessasary that no builders bench should be without.
1. Hobby Knife (Exacto or similar)w/extra blades
2. Hobby Iron
3. Sand Paper 220/440
4. Straight Edge
5. T-Pins
6. Masking Tape
7. Thin CA/Med CA/Thick CA
8. 6 Minute Epoxy/30 Minute Epoxy
9. Balsa Filler
10 Rubber Bands
There are others but I will allow some other people to add to the list.

Not nessasary but nice
1.Balsa Plane
2.CG Meter
3. Incidence Meter
4. Throw Meter
5. Hinge Marking Tool
6. Hinge Slotting Tool
7. Monokote Trim Stripe Tool
8. Clamps
9. Builders Matt
10. Heat Gun
11. etc. etc. etc. etc.