First, I am glad you asked the question, and did not assume that you could ignore even just a few drops of water. You can NOT.
There are many techniques. The age old is simply to stuff some stale bread up into the pipes. After soldering, the bread is blown out through the first faucet up stream. With todays aerators and ceramic cartridges, there can be some problems.
Oatey makes some gel globs that perform like the bread, and then are melted out.
A professional plumber will have tools like a JetSweat and/or a pipe freeze kit.
Most of the time, by shutting off the main at the street and using logic....you can get it drained down. If you are on the first floor, open some cold taps on the second floor to let air in. This will help drain.
If you are in a basement or crawl space, sometimes you can remove some clamps on a long run of pipe. This will allow it to flex down to drain out; then when you lift it back up, you have some time to get the joint soldered before any more water works its way up.
Depending on where the fitting is located, it might be possible to use a compression fitting in lieu of sweat. If the area is not acessible, code will not allow this.
Hope I have given you some ideas. Post back with further details of your project and someone else will have some better ideas to help you.