As I mentioned before, though, there are multiple way to fish this fly. Often when fishing it in a larger river from a boat, anglers will drift the fly before retrieving it. Cast the fly slightly upstream of the boat and use a hi sticking technique to drift the fly along the bottom. After it drifts past the boat, strip it back in and repeat. When fishing it this way, It can pay dividends to lift and drop the fly during the drift. This give the fly a jigging motion that fish die for. This technique can be done from shore too, especially on small to medium size streams. When drifting Dolly Llamas, be prepared to snag up quite a bit.
Another technique popular for fishing Chinook, Steelhead and early season Rainbows is to swing the fly. This can be done with or without a sink tip. With this technique you will be fishing moving water. Cast the fly quartering down and across the run. An upstream mend can be added here to allow the fly to sink. From here allow the current to sweep the fly across until it is directly down stream of you. If you haven't hooked up yet, pump your rod back and forth so that it pulls the fly upstream and allows it to drop back down. You're literally pulling the fly away from the fish and dropping the fly back in its face. Tricky!
Dolly Llamas can be fished with both a straight floating line or with a sink tip. The larger sized Llamas (#4 or larger) are very heavy and can be difficult to cast. Anytime you can get away with using a shorter leader, especially with a floating line, do so. With a floating line, salmon/steelhead leaders of 7.5' to 6' in length are much easier to cast than standard 9' salmon/steelhead leaders. Often the fly will fish better with a 9' leader, but it becomes much more difficult to cast.
We hope that this is insightful.
Best of luck on the water,
Alaska Fly Fishing Goods