Angle iron and flat stock for a simple 90 degree jig. Flip the angle iron either way for multiple options. The angle iron will let you clamp items together instead of trying to fumble around with a magnet.
Veritas® Transfer/Log Scribe :: The Veritas transfer scribe is used for transferring the contours of one shape onto another. This is what makes it an ideal log scribe. But this also makes it an excellent carpenter’s scribe .