Tarp: Decathlon Tarp
I don’t know why I haven't always taken one of these camping with me. It's essentially a large, lightweight tarpaulin, with sewn in eyelets at the corners and along the edges, with a series of long guy ropes, and two long, multi section steel poles. If there are no trees about you can use the poles to hold the tarp up, using the guy-lines to keep the whole thing rigid. If there are trees, just re-arrange the guys and ditch the poles. If you are backpacking and don’t fancy carrying the extra weight of the fairly heavy poles then leave them behind and get inventive with how you put it up. You can use anything really - a wall, bush, bit of driftwood, or even your tent. I guess this is what soldiers would call a 'Basher' (is that how you spell it?). Clever soldiers. Twenty quid well spent.
The tarp itself is 3m square and the poles are 1.8m long.