Cut the limes in quarters, and put them in the jar. The smell of limes makes my mouth water and pucker at the same time, and I can't help just touching the tip of my tongue to the cut flesh. They taste more savoury than lemons, and seem to ask for salt.
Then strain it and leave it a little longer. You can mix it to taste with simple syrup for a sweeter drink, or just leave it bone dry. I fancy it as part of a variation on the dessert Coupe Colonel, which was one of my favourite things last summer: good lemon sorbet liberally dosed with vodka. Don't know who the Colonel was but he can't have been fit to take command after many of those.
Many thanks to the wonderful Danish Schnapps website for this and more, you name it, if it's of vegetable origin anyway, and they'll give you a schnapps recipe for it.