Unlike standard pipe thread like NPT, Garden Hose connections have a rubber washer in the female threaded side. This rubber washer prevents and discourages the use of pipe tape for these connections. Pipe tape and sealants will actually impede on the male threaded side being able to fully seat against the rubber washer. So while common sense says that if a connection is leaking at the threads you should add tape or sealant, but this is NOT true for garden hose connections.
So, if you're having a leaking problem with your garden hose connections, be sure to remove any tape, and then check your rubber washers. It's always a good idea to grab a pack or two from the hardware store so you have extras.