If the weather is anything like it is here, a few blankets would be perfect. It's a lovely sunny day at the moment and I'm gonna take my four year old for a walk in a minute!
When you set your camp, make a mattress from downed limbs. Use large straight branches at the bottom, arm thickness or so. If you use long sticks the length of your body, you can raise these up on two cross beams, just thicker spars laid at about shoulder and knee positions on the floor. This will give your matress a bit more spring and get you away from a damp floor, but they are not necessary. Of course, you need to keep laying these branches down side by side until the bed is wide enough for you.
Once you have the bottom layer sorted, place smaller twigs and sticks running across the bed. Build up a good layer, make sure none are sticking up. Once you have covered the bed with the sticks, place the soft top layer on. I suppose you could use bracken or grass for this but I have always used branches trimmed from a fir tree of some sort. There is always a downed fir tree in the woods, dunno why, but use this tree and get the nice green boughs off to lay on the top of your mattress.
Place the fir boughs into the sticks below so that they are almost stood up, then when they are in they fall down and lay across the sticks and create a nice surface of your bush mattress. Lay one blanket on top, lay on the mattress, place your other blanket on top doubled up if big enough and throw the left overs from the bottom blanket over the top aswell. You should stay lovely and warm!
If you do need a sheltaer above, I would simply take a poncho, if you are out and about you need basic kit and waterproofs should be part of that kit. The beauty of the poncho is that it can be your waterproofs and your shelter, and can be used with a few bits of wood and some string to make a pack to carry all of your kit in aswell! (Don't ask what you do with your kit when it rains though!!)
