I haven't used insulation. I have a blue, foam pad that I've tried a couple of times, but it's awkward to stay on top of and every time I end up tossing it out partway through the night. I don't think I've had to deal with temps lower than the mid 50s, so I've been fine with a summer weight bag and a bag liner. On my last trip I mostly just used the liner. I've seen instructions on turning my Hennessy rain fly into something you can sling under the hammock to hold a pad or other insulation underneath you. I'd like to try that. I also have a large tarp (Gear Guide 12 foot) that is a lot more tarp then I need most days, but on a cold night I could see using the Gear Guide to create shelter from the wind and use the Hennessy fly for some bottom insulation. I could probably be cozy at much lower temps with that set up.

what should i be looking at buying to make a good footprint.

I was using a self inflating pad and it was comfortable. I would open the valve and let it inflate but wouldn't add any more air to it by blowing into it. The only thing I didn't like was the straps and the the valve, I would feel them at times if the pad wasn't placed correctly. I gave the pad to a man I rode with while on tour recently when his air mattress began leaking, and I used a closed cell foam pad. It works alright. I bought it on tour. I have the Walmart closed cell foam pad here at home which is wider and has the alligator like pattern on it. I haven't tried it yet with the hammock. It may work better if it is more flexible than the standard blue pad.

I have the Blackbird Hammock with a double layer bottom so I can put the pad between the layers, that makes it easier to get the pad situated.

I will have to do some test hangs when it gets a bit colder.

I thought about making a hammock with a pocket in it for such a reason. I've also thought about making one with a down layer already sewn on the bottom. But this wouldn't help me when I go to ground (hopefully not much). But my next project (been in development for a very long time, me being lazy) is to make a hammock/tarp that can easily convert to an enclosed tarp tent.

Okay, speaking of going to ground. Exactly how do you accomplish that with your setup? I have yet to do that with mine. Do you carry poles with you?

You can use poles, but another way to do it is to run one end of your tarp's rope/strap over your bike. The other end is anchored to the ground. This makes kind of a lean-to, but with the sides of the tarp also anchored to the ground. I saw a picture and thought that was a good idea.

With my yet to be made ground hammock, I want to design the tarp to have doors so I can be totally enclosed. I also want to but some attachment points inside the tarp so that the hammock and bug net will be off of me. The hammock will have tie outs to also spread it out some. Hopefully if I design it well enough, it will be like a double wall non-self-standing tent. I've thought about using one pole and the bike for support on both ends.

I had seen that picture too. I figured if I did that, at some point in the night the bike would fall. lol I am sure if you have decent tension on it, that wouldn't be a problem. Now that I'm thinking of it, I have thought about getting a clickstand and am wondering if I could rig up a way to use it as a pole if needed.

You could also use some whoopie slings and use them as stabilizers. For example, tie two around the top tube with a lark's head. One to each side. Then tighten to keep upright. Or, if you know the trucker's hitch, that might be a better choice for this. Maybe use two more, one around the bars and the seat post for front and back. Of course, you can use more to make it very stable.