Boulder Creek is really, really low right now. I have never seen it this low. However, the fish are very hungry and looking up. Any depression in the stream bed, I mean no more than a foot or so, is likely to hold a fish or two. But you only get one chance and then the spot is done. If you find a deeper pool, put on a dropper and fish about a foot off the bottom. Above the falls in the steeper sections the water tends to pool more. Move often and make as few false casts as you can to get the most fish to respond. While there are larger fish in the system, you can expect to catch 8-12 inch browns with the occasional rainbow. Get them back in the water fast and pinch down barbs. You may only hook half the fish that come up to the top, but you will get a lot of chances and the action is fairly predictable.
Dries (18-20 parachute adams, 14-16 PMX, 16 elk hair caddis)
Dropper (any small mayfly nymph pattern on 6X)