I find I use a razor saw a lot
right angles, probably 4 or more, for when you are glueing formers.
Pack or two of t pins
I cut small ply rectangles and glue sandpaper to them and glue a sq strip on the back for a handle.
Mini mitre box, they are good but not really req'd

I recently learned about this kit for new builders, which is great for building techniques http://shop.balsausa.com/product_p/426.htm