I have RJ. The hardest part is keeping track of the kerf. When you lay out your joint fingers and then the slots that they go into if you do not take into account the kerf ( the wood sawn away ) the joint will either be too loose or will not fit together. Consistency is the key. If you cut it the same you can make adjustments according to need. I suggest you practice a bit to make them. They really are not that hard, you just need to pay attention to the details.
DW