these are some that I have in the garage right now. Left is a sanding block for sanding the V on the front of control serfaces. The 90 with the quarter circle cut out is for aligning the rudder post when installing. And there is my $.50 yard stick incidence meter. I almost always build to 0,0,0. If I do want to check washout or for wing warps, I use an angle finder. But most time I just level everything with the bubble. It's really pretty accurate, and for the best accuracy you just make sure it is always facing the same direction, everything will be in line for sure that way.

The second picture is my "heavy 90" I cut it into a 2X4 (obviously), tweaked the saw until I got a good 90 (even most of the store bought 90's I have at least a little off!) But it has three different hole sizes in it that I use for soldering bullet connectors onto wires. Just put the connector into the how. and solder away.

Austin