1.Take 1 gallon of gin, 3oz bitter almonds, 3lb sugar, 6 pints of sloes. (some people mash the sloes, but i just pierce the skins)
2.Put everything in a big bottle (or several small) and shake a few times each week.
3.After 2-3 months, syphon off into bottles :-D
Thats a basic recipe, some people like a bit more sugar (to give that thick liquer texture), or different sugars. I use just normal granulated sugar.
The longer you leave it the better it will taste.... and it will keep for years.
Ed