Make some T gauges
If you’re using a T-Plan, cut 20 pieces of your wood, of thickness T, at about 1" by 1/2" (25mm by 12mm).
Glue ten together, then four, then three, then two.
These five gauges will give you any size from T to 20T.
Now use these gauges, INSTEAD OF A RULER,
to measure and mark out the pieces to cut.
T
2T
3T
4T
10T