One of the greatest features of the wooden metal lip swimmer is that the fisherman has the ability to adjust the depth at which the plug swims, on the go. I am sure that countless articles and videos have already been written and produced on this subject, but I feel that it bears repeating. It's a simple trick, and it can be the difference between getting skunked and catching fish.
There are two ways in which a metal lip swimmer can be adjusted to alter the depth at which it swims. The first, is by adjusting the line tie on the lure. Almost all metal lip swimmers come out of the package with the line tie running straight out of the lure. By angling the line tie up, or down, with your pliers, you are able to make the lure swim deeper in the water column, or closer to the surface. When adjusting the line tie up, this will cause the lure to swim deeper in the water column, under the surface. By adjusting the line tie
down, the lure will swim higher up in the water column, or even stay on the surface entirely. The trick I use to remember this is; "Up is down, and down is up." Meaning, if you adjust the line tie up, the plug swims down, and if you push the line tie down, the plug swims up.
The second method of tuning a metal lip swimmer is to adjust the angle of the lip. I think it's important to preface this by first saying that you should never do this unless absolutely necessary. It should also never be done to a fully sealed (aka Jersey Style, where the plug body is injected with epoxy and built with metal hook hangers) lure, as it will leave the lure irreparably damaged. Bending the angle of the metal lip will often times deform the lip ever so slightly, in such a way that it can't really be returned to normal. The bottom bend on the lip will become rounded if repeatedly altered. You also risk damaging the finish, or even the body of the lure, if the topcoat is bonded to the lip. Many builders who offer a lifetime guarentee against defects or worksmanship related errors, will not honor that guarentee if the lip has been adjusted or altered. That being said, by adjusting the metal lip in the same way you would the line tie, you can alter the depth at which the lure swims. Again, "up is down, and down is up." By moving the lip upwards, closer to a 90 degree angle, the lure will swim deeper. If you open the lip up, closer to a 180 degree angle, the lure will track closer to the surface.
These two tricks are simple, but have the potential to help produce fish when conditions change, or when the fishing is slow. Be aware of your surroundings, and adjust your plugs accordingly.