Why are you thinking about a tarp? If your reason is weight, you won't save much over the shelter you are currently using. If you just want to try it out and see what using a tarp is like, try to connect with someone in your area who already uses a tarp and learn from them. If you want the shelter to cook under, definately bring a piece of tyvek or thin plastic as a ground sheet. I'm NOT trying to keep you from using a tarp, but instead to get you think out why and how.