Paco, while I'm certainly not a walleye expert I've caught my share of 'eyes out of waters from Ohio to Michigan to Ontario. I spend most of my time on either Mosquito or Atwood and am not familiar with Berlin either. The things I look for most this time of year are cover and bait. Walleyes are quite often weed dwellers on Ohio inland waters and will also relate to wood (stumps, sunken trees, etc.). Jig fishing weed edges paying particularly close attention to cuts, jagged edges etc. on the edge of the weed bed is a very good starting point. And tipping your jig with 1/3 of a night crawler can be very helpful. Drifting crawler harnesses can also be very productive and in my opinion the less gaudy the better. My homemade harnesses of 3 or 4 beads and a single colorado blade and single hook have caught a tremendous amount of fish and are simple to make yourself.
Trolling this time of year consists primarily of dragging lures along a cover edge (i.e. the outside edge of a weedline) or searching for fish along a breakline. Points along the breakline of a submerged creek bed, rock pile, old foundation, whatever can all be trolled effectively. Sometimes matching the bait produces best - like using a hotntot in a lake where shad is the primary forage. Other times a minnow bait will produce better maybe due to a hatch of minnows or perch. Experiment with different lures until you hopefully come up with a pattern.
There are myriad other methods of taking walleyes but if you concentrate on cover and get good at it you will catch fish. Not every time but you'll do okay and you can then start to expand your knowledge base and learn new techniques.