How do I get better at precise cuts and tricky wood joints?

You can already cut and join wood, which means the foundation is there. Precision and hard joints are a different level, and they come slower for everyone. The people who make it look easy spent years cutting joints that did not quite fit. You are simply earlier on the same road. Precision is less about talent and more about setup and patience. Sharp tools, careful marking, and cutting just to the line instead of through it. Most sloppy joints come from rushing a step, not from a lack of ability. Slow hands make tight joints. Pick one joint that gives you trouble and cut it ten times on scrap wood. Study why each one failed and fix one thing at a time. That kind of focused repetition is how the tricky joints stop being tricky. Your hands will learn what your head already understands.