All of our lakes around here have a TON of submerged vegetation, so I've had to learn it after moving here.
My favorite thing to do is to flip (pitch) it. Use either a heavy 3/4 - 1 oz grass jig (the All Terrain Grassmaster comes through the best of any I've tried with the North Star South Paw coming in second), or my personal favorite, a heavy (3/4 oz) tungsten weight pegged over a punch skirt and Texas rigged plastic of your choice. Those punch skirts help a ton with the rig coming through cleanly - board sponsor ACT Lures makes really, really nice ones for really good prices and will make whatever color pattern you want.
I'll usually start at the deepest point where I can see the tops of the vegetation and go to town. Make a flip, let it hit the bottom, watch your line for jumps, slowly feel for a bite, if none hop it a couple times and let it settle again (still watching that line), feel for a bite, reel it in and flip again. Unless they're really finicky and you've got fish located that need the bait to soak, each cast should take 10-15 seconds.
Almost always my game plan zig-zag across the flats checking different depths until I get bit. Pay really close attention every time you get a bite, and always drop waypoints when you catch a fish. Was it one type of vegetation or another? Maybe it was where two types are mixed? What was the depth? Did you flip it into a clump, or into a hole? Etc. Generally an area where you get bit will have more than one fish, so slow down when you get a bite. Taking into account other factors, once you get a couple bites you can oftentimes pattern them to cover a lot more water. For example, if I've got bites in 7 feet where milfoil and coontail are mixed, I'll run right along the contours at 7 feet and flip everywhere I see that stuff mixing. Sometimes a pattern doesn't become obvious until you go back and look at waypoints - keep in mind that fish use contours on grass "flats" just like they do when migrating up the creek or out in deeper, bare bottom areas. Otherwise those waypoints give you good starting spots next time you're out. Fish around here will often use a spot in the grass all summer.
If it's cloudy and/or windy, you can never go wrong throwing a chatterbait. If the grass isn't close to the surface, usually it's best to let it settle or reel it slowly enough that it's getting hung in the grass, but not so much that it gets buried. When it gets hung, pop it free almost like you're setting the hook on a crankbait. Pause for a split second after ripping it free as this is usually when something train wrecks it. A lipless can be worked this way as well, but I've found that when the water warms a chatterbait seems to be best. A swim jig a little more subtle way to get through it. With that, I'm only "ripping" it if a piece of grass comes free and hangs on it, else I'm just working it back to the boat like you'd fish a spinnerbait. A fluke is a no-brainer as well.
If they're wanting something more finessey, a light (1/8-1/4 oz) pegged Texas rig or even a drop shot with a cylinder weight and Texas rigged plastic can work extremely well. Same story as the chatterbait, but much more subtle - (gently) pop it free of vegetation and just let it sit for a second or three. Continue working back to the boat. m
Another similar technique is what folks around here call a "jig worm." It looks like a Ned rig, but uses a heavier jig head with a longer shanked hook. Z-Man's Power Finesse Shroomz are a good example. For that you want a bigger worm, say a 7" Power Worm or a Senko. Cast it into the grass and you almost want to drag it like you're fishing a football jig or Carolina rig until it hangs. The aim here is to intentionally get it hung in the weeds, then pop it free. They'll often crush it when it pops free, or you'll otherwise go to pop it off of a weed and suddenly be fighting a fish. It's somewhere between the chatterbait and light Texas rig / drop shot I was talking about above. It sounds crazy to throw a big exposed hook into vegetation and intentionally hang it up, but it'll shock you how well it comes through.
Tons of ways to fish it. My biggest obstacle when I started learning to fish grass was getting away from the idea that you have to keep your bait free of it. Most bites will actually come when you're
in the stuff, or at least ripping free of it in my experience, and I was really surprised at how cleanly you can get a bait through it, particularly if the grass is healthy. You might be surprised how well you can fish your favorite techniques to use in other places right through the grass.
Sorry for the book - I'm procrastinating today, and also remember how daunting learning to fish grass was when I first moved to Minnesota from West Virginia where we had basically no grass at all. Thank goodness for Bassmaster Live and getting to watch those guys do it as well as some really awesome guys in my club who offered some tips, cause most folks around here are more happy to politely take your money than to teach you how to beat them! I suspect that's pretty universal after typing it out....
Hopefully some of that applies to what you're looking at!