The following is from Lefty himself:

To build a good inshore leader of approximately 10 feet for an 8- to 12-weight rod, I suggest using a 5-foot butt section of50-pound test. Add a 2-foot section of 40-pound test, then about 18inches of 30-pound test followed by a short length of 25- or20-pound test. So long as the butt section measures one-half theleader's length, it won't matter if the other sectionsare off by a few inches. The tippet should not run more than 18 or20 inches. Longer tippets tend to develop wind knots more easilyduring casting.

The best monofilament to use is premium spinning line, and it isimportant that all sections of the leader be constructed from thesame brand. I recommend blood knots to connect the various lengths,although a surgeon's knot is OK in lines testing 20 pounds orless.

Its also fun to learn how to tie droppers into the leader. You can do a google for Ken Abrames droppers.