>>826034I alway use flouro for leaders. Maybe 3' if the water is really clear and I'm worried about visibility. Maybe 1' if I don't want to cast through the knot. Sometimes no leader at all and I never have an issue.
I do uni-uni knots for the leaders because I can tie them well. The two others people mention a lot are the FG or Albright. One of those is really complicated, can't remember which.