First rip all your boards to 2" wide. I used poplar for my styles and rails because its cheap and I new the doors would be painted. next cross cut your styles (vertical pieces) to the exact length you need for your cabinet. next cross cut the rails to the width you need for your opening minus the width of two of your styles (4") plus the width of your tenon times 2 (3/4"X2) plus the width of your rabbit times 2 (3/8X2).
You could cut the rabbits before you cross cut all the lengths but I find it easier to manage if you cut the rabbits after you cut all the lengths. I cut my rabbits at 3/8" by 5/16" by first setting the blade height to 3/8" and setting the fence 5/16" and making the first pass on the boards edge. Then I laid the board on its flat and set the blade height to 5/16 and the fence to3/8" minus the blade thickness (just measured to the opposite side of the blade) and made the final pass.