This is my method for sloe gin:
Put 500g (1Lb 2oz) frozen sloes and 250g (9oz) granulated sugar in a 1.8L clip-top jar (Ikea sells these - haven't found anywhere else the does them that size, but you can scale up or down easily enough as the proportions are basically 4:2:1 of booze:fruit:sugar, and only need to be approximate). Cover with 1L (1.7 pt) gin, then fill up with sloes until the liquor is about 5mm (1/5") below the mouth of the jar. Close and label the jar, shake daily for a fortnight, then leave in a cool dark place for at least two months, but preferably at least a year. The longer you leave it to steep the more almondy flavour you'll get from the stone.
You can use the same basic recipe and 4:2:1 quantities for blackberry whiskey (don't leave the berries in more than two months; Irish whiskey works better than Scotch whisky) plum brandy (the drained plums are great for jam or a boozy pudding) spiced apple vodka (bramley's, cox's, crab or cider apples, plus whole cinnamon sticks and cloves) rhubarb & custard liqueur (vodka, rhubarb and a split vanilla pod) or rosehip liqueur (dog-rose hips and vodka).