SCARFING BY HAND

Note: The angle shown here is too shallow for structural work, you need at least a 6:1 ratio for mast timber, if you can do 8:1 that would be better still.

It's not a difficult thing to do though, simply mark the line and cut. If you have enough space and a good vice, you can hold the two pieces you are going to join one above the other, so that they are in line and overlapping where the joint will be, and cut through both. Even if your cut is a little off square, they will both be in line, and you'll get a near perfect join.

I'm not sure if that description makes sense, if not, ignore it and do it your way!