I use 9 lbs (before stoning) per gall of wild red plums to make a wine that's very, very, plumy indeed (most recipes state between 4 and 6 lbs).
Damsons seem to be everywhere this year, and sweeter than normal (could be a real vintage year), so I'm going to make some using the same method as for red plums:
Remove the stones (essential as they will taint the wine), put fruit in freezer then defrost (to break up fruit), put in covered bucket, mash and add with 4 pints cold water/gall (you should get about 4.5 pints of juice/bulking from the sugar, add crushed campden tablet & 2 teaspoons of pectalase (high pectin fruit), stir in, leave 24 hrs, add yeast nutrient & yeast, ferment for at least 3 days (stirring several times a day) to get colour from skins, strain onto 2.5 lbs sugar/gall, pour into demijon (top up with water if your extraction was less than anticipated) & ferment out. Or add half the sugar once it's been fermenting for 24 hrs in the bucket, so it's not so vigorous in the demijohn.
I avoid any method using boiling them as it will release pectin and can cause clearing problems.
Damson jam is good, and we are also going to make damson chutney (WI Best Kept Secrets - Orchard Cottage Chutney/River Cottage Cookbook - Glutony - virtually identical recipes), as we made it using wild red plums last year (but I have used them all for wine this year).