One of the most simplistic and least used fishing rigs can also be one of the most effective. The free line rig isn’t much of a rig at all yet it can work incredibly well.
The free line rig is exactly that. A line that floats freely in the water. Tying it requires nothing more than affixing the main line to the hook.
Of course this rig can be modified in ways but the main thing is not to over complicate things. At most, you might want to use a blood knot to attach a lighter leader to your main line.
The free line rig can be used in any number of circumstances. You can toss worms, crickets or artificial lures to panfish and bass in ponds or rivers. You can cast a free line rig with a minnow out to any fish eating species. You can free line corn or bread to feeding carp. You can free line heavy baits like dough balls that provide their own weight out to carp and catfish too.
If you toss a free line rig out in still water like a pond or small lake the bait will eventually settle to the bottom. Normally you’d want to use it in some fast and furious action where the bait will be taken before it ever gets that far.
If you need a bit of weight to help you cast further or get down deep you can attach a few split shot to your line or use a weighted hook like a jig head. These will interfere with the natural presentation you get from a free line rig but sometimes they are necessary.
In moving water you can toss a free line rig upstream and follow it downstream. Fish can grab it anywhere along the drift. If the water is too fast or deep, or if the fish are holding down around the bottom, you would be better off using a slinky drift rig. If you don’t want to feel your line or watch it to indicate bites, you should use a floating drift rig.
When using lures like spinners and Rapala minnows a lot of people simply tie them directly to their main lines. This could probably be considered a form of free lining depending on your perspective. If you use things like swivels that would complicate things but possibly help with action or line twist.