Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
This is tied on a VMC 4/0 Trailer hook. They are much cheaper than most big fly tying hooks. I think the next one I tie will be on a Daiichi 6/0 so I have room for a spun hair head too.
Eric - I have not used those. I will check the local shop and see if they have them next time I'm there. I do love Gamakatsu hooks!