I used to make sloe gin with fresh sloes, when we lived near the New Forest. It was a delightful pink colour.
Put your sloes in a screw top jar, cover with sugar, add gin (any - I used cheap stuff) to comfortably cover.
Shake the jar every time you walk past past. After a couple of months or so, strain off and bottle. Sweeten/fortify to taste. Leave to mature for as long as you can bear.
It wasn't terribly scientific, but after a glass or two who cares?

You can buy dried sloes, but it's not the same. The colour is brown (commercial sloe gin is often brown) and the taste wasn't the same.

Be careful if you pick sloes - the thorns are absolutely evil, straight and strong, wounds hurt like mad and take ages to heal.

Malcolm