Don't forget about the decreasing daylight though, always ensure you have enough time to make it back to your car (either before dark, or before they close the gate!). The forecast Sunset time is pretty accurate, but you still have about an hour of useable daylight after the sun has disappeared over the horizon. In the trees, it can get darker much quicker and you lose your depth perception making it harder to spot tripping hazards. So even if you will be off the trail before it is officially "Dark", a headlamp or flashlight is a good thing to keep in your day bag.
The trails become more slick in the fall, so investing in a good hiking pole is a great way to stay on your feet! Ive been using the one pictured below for a few years, and really like the cane-style handle rather than the traditional Ski-pole style, it gives me a good handle when Im climbing steep terrain, and just feels more natural when walking. Everyone falls on the trail, its just a matter of time. Having one of these in your hand could save you a sprained ankle or dislocated knee. It also makes you look like eat mountains for breakfast!!