Location is everything when it comes to fishing - the best lure in the world can't catch fish that aren't present. There hasn't been a body of water I fish that doesn't have flats and a type of flat I call a shelf. My definition is a flat bottom that extends from a shoreline at a certain depth and then drops into deeper water. The shelf can be 4' or deeper but always drops into depths greater by at least a few feet if not more.
The shelf can be narrow -30' or wide - 30' or more. When fish relate to the shelf, they can be close to the shore, suspended over the shelf away from shore or near the edge of the shelf as it drops in depth. Today I caught fish within 20' of the shore over a 20 yard wide shelf in 5' of water. Fish were also caught near the edge of the shelf that dropped to 7'. The area yielded 10 fish - perch and crappie.
A shelf has a beginning and end along the shore and another shelf may not occur for another 30 or more yards along the same shore depending on a shoreline's configuration. A shelf may end at a point of land after which deeper water and a steeper shoreline exists until the next shelf. The shelf in the above example was 30 yd.s long.
As soon as I catch fish over a shelf or near it in deeper water, I anchor and keep casting to that area in one direction - hopefully the same exact spot I caught the first fish. Today one fish led to two or more fish in the same area and after catching those fish, I did an about face and fished in the other direction parallel to shore, catching a few more relating to the shelf's edge. The water temperature was a cold 39 degrees, but the bumps felt were strong allowing me to reel fast while pulling the rod tip away from the fish (which didn't even feel hooked until they panicked), allowing for a final hook set. Some fish hit two or three times on the same retrieve, not wanting the lure to get away!
I fished other structure types and depths in the morning and caught nothing. Besides that, no bait fish were seen on the sonar. As I drifted to the north and found shelf structure, baitfish schools were evident and fish were caught. Before the wind got really nasty blowing near 25 mph or more and forcing me to quit for the day, over two dozen fish were caught. Crappie in different sizes, decent perch and a few bass and sunfish - most caught on Crappie Magnet and on my hand-pours grubs rigged on 1/25 oz jigs, but the Magnet got the strongest hits.
Here are examples of locations adjacent to the shore:
https://i.imgur.com/E7YWc4i.jpg
Note where the largest tree is in the distance. Just beyond that is a wide shelf only 3.5' deep that drops down to 8'. There were no fish on it or in deeper water. From that tree to where I anchored, the shelf was 20 yards wide and held fish. This is shot looking towards shore:
https://i.imgur.com/a9zV7Zd.jpg
The fish were not in the lay downs but on either side within 10 yds. from shore and in deeper water on the shelf's edge.
Looking north,
https://i.imgur.com/ZTFvgDe.jpg
the shelf ended and I found another just after the fallen tree in the distance. Cove shelves (inlets) were found along this shoreline along with century old rock walls extending into deep water. Some coves held 8 fish. This was the typical sonar image of the shelves I fished (flat with rocks sometimes and little vegetation.
https://i.imgur.com/w9W8BOd.jpg
The air temperature got to near 60 but the water temp averaged 39-41 degrees - kind of chilly due to a 20 mph wind blowing the whole day across cold water.
My lure of choice were grubs rigged on 1/32 or 1/25 oz jigs and a 6# test fluorocarbon leader (with braid the main line).
https://i.imgur.com/RPj811c.jpg
The nice thing about the 1.5" cone tail grub was the action on the slowest retrieve - something I must always remind myself to provide cold water fish. 1/16 oz might have worked, but since the plastic had salt added when I made it, it weighed enough for casting distance and sink rate.
Others may have a name for the type of locations I targeted fish - over two dozen : crappie, yellow perch, sun fish and bass, but you get the idea. So far this pattern is applicable to mid fall fishing; I find fish in other unique areas other months of the year. You might consider all of this if you have a boat and use sonar to track depth.

