Been a couple years since I fished up there..here's my recall.
West slope of Sierra through mid-summer is predominantly caddis...variable colors. Most bugs coming off in the afternoon, but no real dramatic hatches.
favorite dry for me was a goddard caddis, but elk-hair would work, too, as would henryville special etc etc. I preferred the goddard, as I was fishing mostly freestone streams and the floatability helped...
Variable mayfly hatches, in a variety of colors...some yellows, light tans, grays and periodically white bluewing olives more at the extremes of the season.. Any mayfly pattern in a reasonable color would be OK..an Adams would cover most bases.
For size...mostly smaller bugs...sizes 14 and 16 were the most common dry sizes for me out there.
nymphs can be VERY productive...on the bottom...turn over some rocks to see what you are looking to mimic....should find scads of caddis pupa and nymphs, especially the little guys with the stick or stone cases..in many areas, it's hard to wade without stepping on them.
Common dropper rig for me would be a dual setup of a GRHE and a prince...typically one in a 12, the other a 16 or 18...would commonly split between the flies fairly evenly.