Different lenses will allow for different creative options. A wide angle lens in the 15mm to 28mm range will capture more of the classical compositions of the dunes while a telephoto lens would be useful if we happen to see some wildlife. If you have both and decide to bring them, remember that we will be doing some exploring away from our cars.
The weather this time of year can change pretty quick and the winds can easily create blowing sand so having some sort of lens filter (i.e. an UV) is strongly recommended. Rain and snow can also be an issue so a good weather proof camera bag can help protect your gear if we get wet. Bringing a plastic bag is also a great idea to help protect your gear in both wind and wet conditions and can be easily stored in your camera bag. The temperatures can vary from the 30's to the 70's so dressing in layers will help you stay comfortable as the temperature changes. Wearing a hat and sun screen can help you save yourself the discomfort of sunburn.
Water! Hydration will be very important, especially for those of you coming up from lower, more humid, elevations. It is easy to get dehydrated in the high desert climate, so be sure to drink water often and always have some with you.