What should be done to the nails before preparing for an electric file procedure?

Before preparing for an electric file procedure, it's important to file the nails down to an appropriate length and shape. This step ensures that the electric file can effectively and safely smooth and shape the nails without the risk of damaging the nail or causing discomfort. Filing helps to remove any excess length and creates a manageable surface for the electric file to work on.

Addressing the other options, moistening or soaking the nails is typically not recommended before using an electric file, as this can soften the nails too much, making them more susceptible to damage or tearing during the filing process. Buffing the nails, while it can be part of nail preparation in other contexts, is not necessary prior to using an electric file and may even interfere with the desired results from the filing procedure. Thus, the most appropriate action to take prior to using an electric file is to file them down.