makeing my strawberry's sweeter?

I remove the stalks from the strawberries, then wash them well. I leave the water that's clinging to them after washing on them, then I make a small incision in the top (where the stalk was) on each strawberry. I put them in a dish and sprinkle sugar all over them, then leave the dish in the fridge to chill for at least 3 hours. I find they come out nice and sweet, but the smaller strawberries are naturally sweeter than the large ones, so when buying them, I try and choose small ones.