Tarps: A tarpaulin, a length of good rope and pine-needle mattresses make for cheap wrap-’n-roll shelter that won’t gobble up your wallet. But if you want to surprise the sunbirds with spiffy-synthetic-domicile, your choices are backpacker tents (heavy but cheap), wind- and cold-resistant tents (pricey, light and cosy), family-size (one snorer disturbs all) and pop tents (instant housing for the lazy).