When the storage image darkens, indicating it's ready to receive the file, let go of the mouse. This method can be a little tricky, because now you have an exact copy of the original file. The next time you make changes and save, it will be placed in that location. Be careful to keep track of where you saved the file, because this will be the most recent version of it. You also run the risk of having multiple copies of the same file name in various stages of production.
Several programs have an instant save feature that can be activated.
Name your files using easily remembered names. For important data, you may want to save in several places. These are remote servers that can be accessed from any Net connection. Again, you won't want to save huge files here, as there are size limits, but they are convenient ways to store data. For a fee you can even expand the size of your personal iDisk.