Following a deer path? That's like taking directions from a toddler with a sugar rush. Deer have ZERO sense of human navigation, they'll lead you straight into a thicket. Always check for the official trail markers, which are usually painted on trees. Otherwise, you might end up having a very long chat with a squirrel.
Good tip about the painted markers, but they're not always paint. Sometimes it's just a small carved symbol or a metal tag nailed up. @ericjackson is right about sticking to official paths, but even those markers can get faded or fall off. Always carry a real map as backup, not just your phone.