Streamers are fun to fish - you don't just have to dead-drift them and get a presentation just right to get a fish to hit them. Like you say - they imitate bait fish, or leeches, or worms - things that move around in the water.
If you're fishing small creeks, that are generally shallow, I like to fish up-stream, or up & across and let them swing down. On an upstream approach - I'll cast to the head of a run or pool, give the fly time to sink down in the water colum near the bottom, and twitch and strip the fly faster than the current.
For a swing approach - quarter a cast up and across stream ahead of where you think the fish is. This gives the fly a chance to sink down - then let the fly swing all the way down past the fish, and keep letting it drift until the line comes tight straight down stream of you or hugs the bank. Be prepared for a strike at any point in the drift - but especially near the tail of the drift - as sometimes the fish will see the fly, and chase it as it escapes. They'll hammer it when it starts to rise toward the surface.
Or you can cast it across stream and strip it cross-current near the surface, or cast slightly upstream so it will sink, then strip it across the current back toward you.
In slow water - treat it like I still water, cast, let it sink, then retrieve it with twitches, pauses, and strips - change up your retrieve until you find what the fishies like.
Streamers are one of those flies that we can have a lot of fun with - because they can be fished pretty actively, and the takes can be really strong.
One of my fav. memories - and the one that seriously got me hooked on the Woolly Bugger as my absolute favorite fly - was fishing the Yellowstone River, and finding a pod of nice yellowstone cutts that were ravaging my bugger. I was just swinging the fly through the slot they were holding in - right at a drop off a little ways out from the bank. I was casting upstream and letting the fly swim down the run, then I'd let it swing tight up against the bank (where there was an overhanging tree providing shade). If they didn't hit mid-drift, there was almost always a strike at the end of the swing, or just when I'd start stripping the fly back toward me before picking up for the next cast. I caught six or seven fat fish - the smallest of which was 14", my big one was just a hair under 21" - in half an hour of fishing. I missed a lot of strikes because I either had too much belly in the line (got to keep that under control) - or because I wasn't expecting them to hit when they did, and failed to set the hook in time.