I'm planning a 4-day/3-night backpacking trip and I wanted to ask for some advice. I've done extensive hiking and camping but backpacking is still a little new. I did three 2-day/1-night trips last summer but an extended trip is something new. I'll be in the Smokey Mountains at 4000-5000 feet and traveling 27 miles. Also, there are many stream crossings - mostly on day 3. Any advice for an almost-rookie on his first long trip? Anything I should expect that I did not encounter on the 1 night trips?