Glad to hear you have discovered bilberries. A few years ago I was gobsmacked to find someone who had never heard of them, but he came from an area which had none. It had not previously occurred to me that there was such a place.
There is a long-standing tradition of bilberry-picking around here, although it is in decline like most traditions due to the growth of our telly/computer game 'living by proxy' society.
The correct way to pick sufficient bilberries is to con several people (children are easiest) into helping, then keep the lion's share for yourself. My family is wise to it now, so I am starved of bilberries.
Best to bake them in pies with plenty of sugar. Very succulent indeed. Blueberries are absolutely nothing by comparison. As mentioned earlier, some people mix with apples to spin them out but to me this is making a sow's ear out of a silk purse.