dig a hole - the dimensions are of relative unimportance as long as you can make it a minimum of 7 feet deep and 5 feet wide. enter it, feet first, then from the inside attempt to build a roof out of grease-proof paper. this will give you some sort of translucency so that you're away of what time of day it might be. stay there for anywhere between six minutes and thirty years. there will come a point where the essential human spirit bursts into action and makes you realise that you need to engage in coitus endlessly, in order to prolong the human race and your very own genes. if you have no spade or other such building equipment, you can visit certain areas of london which seem to develop such urges in young women as, or even more, easily than the technique mentioned above. if you do decide to go with the latter method, however, do be sure to equip yourself with at least six two-litre bottles of cider (which must not cost more than 10p each).
or just foreplay, as someone suggested.