This is updated video of how to make an emergency shelter from single 2x3 sheet (tarp). It is done in less then 3 min and costs about £2.
In short, 2x3 m (6x9 ft) tarp (tarpaulin or any other waterproof and strong enough material cut with sides 2 by 3), 2 sticks at 1.2 m (or 4 ft) each, 2 pegs (or just sharpened pieces of wood) and piece of string are used and the pitching up should take only a couple of minutes if practised. It could be used as rain-cape or hammock, weights around 350 gr and is very compact and light compared to the retail tents. For more details: http://www.farstrider.co/2017/03/tent-fully-enclosed-with-floor-from-2x3-tarp.html
See another set up made from a square tarp http://www.farstrider.co/2017/03/tent-fully-enclosed-with-floor-from-square-tarp.html
It is one of the things that everybody interested in surviving and travelling through the wilderness must know how to do.
Edit: It does not leak from the hole in the middle of the tarp, even in heavy rein. The top looks open, but it is not, it could be rolled up and closed easily.
Edit 2: This is to show the idea how 2x3 sheet is folded in pyramid, there are many improvements that can be done, according each taste.