Things You'll Need
High-quality caulking gun
Silicone caulking is one of the greatest inventions known to man, as it keeps water from seeping out of sinks, bathtubs and shower stalls and into the surrounding walls. But applying it can also be one colossal headache, since silicone caulking can be a difficult substance to work with--and most caulking guns are no help. So how do you do a professional-looking job without calling in, well, a professional?
Buy a high-quality caulking gun. Cheap caulking guns with unreliable triggers will give you an uneven line of goop that's next to impossible to smooth. The same companies that make cheap guns under $15--including Cox and Newborn Brothers--make good ones that cost two or three times as much, but it's an investment that's well worth it.
Let the area where you plan on doing your caulking dry completely. One of the biggest reasons caulking jobs don't "take" is moisture, which prevents the silicone caulking from making a secure, permanent bond with the ceramic or rock tiles. And how many do-it-yourselfers have applied silicone caulk to a tub and, while trying to smooth it, found it adhering better to their fingers than to the tile? Use another shower or bath in the house for a couple of weeks prior to your caulking job, or else do it as soon as you come back from vacation.
Cut the tip of the caulking tube no more than 1/16" wide. The bigger the hole, the more goop--and the more goop, the more difficult it is to achieve a smooth finish. You want a tiny, even bead of silicone caulk for proper smoothing.
Using your index finger, press into a corner and run your finger along the joint to which you've just applied the silicone caulk. Move your finger slowly but steadily toward you. If you've followed the previous step's advice, no silicone will be spilling out from the sides of your finger. There will be just enough to fill the crack.
If you still end up with a little excess silicone caulk smeared onto the tile or top of the tub, shower or sink, remove it promptly with a rag dipped in rubbing alcohol. Do not let it dry; if it does, you're going to have to call in the razor blades.
Wear safety glasses as you caulk. The fumes released by curing silicone caulk can irritate your eyes, particularly if you wear contact lenses.