Indicator fishing can be an incrdible way to maximize your catch with trout but it doesn't have to stop with the bobber. There are a few fun ways to effectively fish wet flies without a strike indicator
First the czech nymphing style is a very popular technique developed by the eastern european competition fly fishing teams which utilizes a long leader and one or two weighted flies. Tungsten beads are a great way to have a heavy fly that will sink fast and easy to cast on a light rod. We also like tungsten flies tied on a jig hook to help reduce snags and get a really solid hook set.
Often fished on slighty longer rods like 10' or 11' 3, 4, or 5weights you can use the extra length to hold most of the line off the water and have a straight connection to your flies. With a long leader and maybe just a few feet of fly line out of the tip of the rod this method allows you to get your flies down fast into a small pocket. With a short tight lined drift you can usually feel the eat or sometimes slowly lift the rod towards the end of the drift and false set to induce a strike. For a little added assistance we will sometimes tie a short butt section on the leader with bright green or red colored amnesia to have something for your eye to focus on.
Second the technique of swinging wet flies in particular soft hackle nymphs can be very deadly as well. This method has proved very good for me on small creeks, where a back cast is problematic, so you can just roll cast downstream and mend your line into position. Typically swinging flies you are focused more on getting your cast quartered downstream and pointing the rod straight below you to allow your flies to swing across the current. Many insects like caddis in their pupa stage move pretty quickly through the water column on the way to hatching into an adult so this helps mimect that movement.
I had a very good day on the Upper Madison a few weeks ago with a friend who fished a big articulated streamer trailed by a smaller nymph with no indicator. Pretty much the same style as you would with an indicator and that also proved quited productive. In shallower water a lot of times you may see the fish flash as he turns to eat you fly before you see the line or anything move.