Using Time Machine
If you are using Apple's Time Machine to backup your computer, you don not have to change anything. Time Machine will automatically backup the Snippet database.
Should something happen to the Snippet database. Open a new Finder window and navigate to your Home Folder > Library > Preferences. Open Time Machine while in this directory, and restore the SnippetDB.plist file from the time you desire.
Using your own backup method
Snippet's database is located here: