Flip,
Think in terms of four categories: dries, emergers, pupa, and larva.
Then consider how you expect to fish 'em and under what conditions. Because midging runs the gamut from deep nymphing in heavy rapids to sippers in frog water, you should have more flies based on expected conditions. For me, most midge fishing is really stick nymphing on the bottom, so I use a lot of Zebras. I fish midge dries much less frequently.
Here's my midge box. . .
The flies range in size from #16 down to #32.
At the top are dries. I like midge dries in cream and black (or dark gray). Tie 'em sparse; some of my midges are palmered hackle and others a puff of CDC. They are mostly 22-24.
For emergers, any tiny fly with a soft hackle will work. keep 'em sparse and dark colored and use floatant on the leader or hackle. There are some good CDC midge emerger patterns. Remember, midge pupa are wiggling, skinny critters and are not as scruffy or thick as caddis pupa.
For pupa, I tie basically the same as emergers but maybe with a tiny bit of weight. Keep the pupa skinny and with clear segmentation. Most of my pupa are #18-22.
For larva, Zebra midges or any variation will work. Have some in red to mimic "blood worms." As always, keep 'em slender and I prefer smaller beads for the head. Most of my midge larva are #18-20.