I use a table saw to make my parts, and use a sled which is perpendicular (90 deg) to the blade, and with the blade tilted at 45 degrees. The angle of tilt is not critical, you just need to use the same angle for all your cuts.

I start off cutting 9 (8 + 1 spare) Walnut parts which look like the trapezoidal part shown. Note the small flat part at the top and the larger flat part at the bottom. I use a stop block (shown on the right side of the blade) so that all the Walnut parts are alike.