Write an article based on this summary:

Check the toilet for wobbliness. Purchase stainless steel washers or plastic shims from a hardware store. Remove the bolt caps and loosen the hex nuts. Add stainless steel washers or shims to the bottom of your toilet. Re-tighten the hex nuts. Caulk the toilet to the floor if the problem is fixed. Continue adding steel washers or shims until the toilet feels even and level.
Sit on the toilet and rock it back and forth or side to side. If you notice shaking, your toilet may need minor or serious leveling. Start with small adjustments and, if the toilet still feels uneven, move on to more extensive adjustments later. If you are trying to make the toilet completely level, use a carpenter's level to measure how close the floor is to even. Plastic shims are made specifically for leveling toilets, but stainless steel washers can work just as well. There are 2-4 bolt caps on both sides of the toilet bottom to secure it to the floor. Take off the bolt caps to reveal the hex nuts, and loosen them with a wrench. In some cases, the toilet may be wobbly because these nuts are loose. If that's the case, simply tighten them! Wedge a few shims or washers in between the floor and bottom of the toilet to make your toilet even and prevent rocking. Try adding 1 or 2 first, then add more later on if the ones you've added don't do the trick. After you've wedged several shims or washers under your toilet, tighten the hex nuts again with your wrench. Place the bolt caps on top of the hex nuts to keep them secure so they don't loosen later on. If adding washers or shims fixed the problem, the only thing left to do is to caulk the toilet the the floor. Use a caulk gun to squeeze a bead of caulk around the base of the toilet where it meets the floor. Smooth out the bead using your finger, then wipe your finger on a wet rag. Caulking the toilet keeps the shims and washers secure in addition to preventing moisture from getting trapped under the toilet. If your toilet still seems wobbly even after adding multiple washers or shims, you may need to make larger adjustments. Remove the toilet to work on the closet flange if adding washers or shims has no effect on how level it is.