As Summer comes to an end, the grass in your lake should be reaching peak maturity. if you live where hydrilla and milfoil grow, mats of the stuff should be on the surface. hydrilla will mat up on the surface but creates voids underneath. Bass use these voids for shade and also cover for attacking prey.
early in the morning i like to throw topwater around the edges of the mats to get fish that our on the outer or inner edge feeding. typically, the fish will be on one side or the other, so you should try both until you develop a pattern. one of my favorite ways to catch bass on calm mornings around mats is using a popper or a frog. buzzbaits work good here too, and usually draw the bigger bass. Yellow Magic baits are the best poppers I've ever used. They have great presentation in the water, a bucktail on the back hook, and the sharpest hooks I've ever touched.
Once the sun gets up, bass will typically move back under the cover of the grass for shade and wait for bait fish to come by. This is where punching becomes the bait of choice. if you were able to get on fish early, you know they are there later. It's a matter of finding a pattern in the grass. Typically, i look for holes, changes in vegetation, hard edges or any variability in the mat that might draw fish. For example, is the mat on a ledge with mussels or gravel? does the mat create a point or pockets that might hold fish? If you can key in on these areas, generally you can find what they like and get on a pattern. be sure and check both outside and inside edges.
for the actual punching, blackout tungsten punch skirt or tungsten flipping weights are the best option. depending on the thickness of the cover, I usually start with a 3/4 oz weight and work up. only use what you need to penetrate into the mat. if using a heavier weight, you can bulk up your bait to slow the fall. if you are dealing with pennywort or really thick vegetation, move up to 1 1/4 or 1 1/2 oz weights.
you always want to use braid when punching in thick stuff, especially if pads are involved. if you've ever tied braided line, you know it cuts into your skin. it really seems to cut into the crease of your knuckles on your index or pinky finger. Braided line does the best job of cutting stems and stalks to get fish out and move them quickly so they can't bury into the slop. use at least 60 lb braid and i recommend a bad mofho flipping hookpegged under a blackout tungsten weight.