I've been doing some o̶b̶s̶e̶s̶s̶i̶n̶g̶ research about still water fly fishing and I've picked up a few pointers I thought I'd pass along. I found a great Orvis podcast with guest Phil Rowley from 2011 on still water fishing that I highly recommend to anyone doing some reservoir fishing, even if you don't fly fish.
First thing- using a strike indicator. I had really just been thinking about casting and stripping streamers, but it seems that nymphs or leech patterns under indicators are really effective early in the season. A midge pupa, scud, or hare's ear could work here, especially as a dropper from a small wooly bugger. A quick release indicator (it will snap off and slip down the line when you set the hook) is useful here, as we're looking at suspending your presentation at 10 feet or deeper in a reservoir scenario. Browns could be anywhere in the water column during the spring. A fish finder is going to give you a pretty good idea of where they are holding if there's any kind of thermocline.
Second, slow presentation and stealth. Just like winter stream fishing, these cold water fish aren't going to chase down a streamer. This makes the indicator technique really useful- even with a streamer. With a little breeze, and some luck, a nice slow drift should produce enough movement to get it in front of a fish. And with regular streamer presentation, a super slow retrieve is key. A fluorocarbon leader is a must in clear water, a nylon leader is fine- but use at least 3 feet of tippet.
Third, those rises I've been wondering about are most likely related to midges. Reservoir brown might hit any number of dry patterns, but midges are everywhere on lakes and might just be worth a shot for those early morning risers.
Orvis Stillwater Podcast with Tom Rosenbauer and guest Phil Rowley