I rarely, if ever, fish streamers, so it's dries and nymphs for me with some wet fly swinging in the early season.

For all three, I can get by with the same leader chassis:

3' of .022 Maxima Brown
2' of .019 Maxima Brown
1' of .017 Maxima Brown
6" of 0.13 Orvis SuperStrong
6" of 0x '' ''
6" of 2x " "

To this basic chassis, I'll tie a loop and then add:
6" of 3x or 4x Orvis SuperStrong
2' of 4x-6x Orvis Super Strong for the tippet

I'll cut the tippet back to about 8" if nymphing.