One thing you should do is turn over rocks in the streams you are fishing and look for life. Tie something up that imitates what you see. Beyond that...
You should add the Two Bit to your box for sure. I don't see any Prince on there either, or caddis larva. I would add those too. Mind you I don't fish where you are, but these will catch fish just about anywhere. Scuds/sow bugs are a must have, especially for spring creeks. The Tungsten Torpedo is another one that's been very productive for me. Slim bodied flies with good weight to it really get the fly down where you want them.
Tie some flies with tungsten beads or double tungsten beads--like the Two Bit I mentioned. That will help get the fly down deep. That fly has caught more fish than I can count since I introduced into my rotation. One day I fished a Two Bit for 3/4's of a day (sun up to sun down) before it literally unraveled on my line. I promptly tied on another and continued to land fish.
The other suggestion if you don't already have it, buy or read George Daniel's book, Dynamic Nymphing. I consider this book a must read for any nymph fisherman. One of the very best fly fishing books I have read. There are tons of techniques in there that have really helped me improve my nymphing. There are also a lot of flies in the book. Some of which I've tied, others I haven't yet tried.