Like a real Flatfish, it can sometimes circle off a bit that's ok, it's part of the charm. A fast retrieve will usually send it a bit deeper than a slow one. Should it surface, nudge it a bit until it is oriented correctly, then slowly start reeling in. Immediately starting to reel in when the lure hits the water usually will result in it diving appropriately.

The only trick to fishing this lure is keeping it from going belly-up on the surface. Notice that the fifth fish of the day actually broke one barb off the center treble hook, but otherwise the lure has been fine after being wacked by eight bass. Update: Well, it's April 12 and in about an hour of fishing I've caught another half dozen bass on this lure! It rides better with a little weight in the front, as suspected, although the sliding weight shown in the last photo didn't work as well as a little crimp-on I'll no doubt be tweaking this design. The photos show how the hooks slide away from the lure to ease release of the fish while fishing, the hooks are against the lure body as they would be for any other lure. Anyway, it still works, and the fact that the fishing line can slide through the body a little makes it easier to deal with unhooking the fish. I thought that would help keep the motion natural, but I now suspect that the weight of the screw-eyes actually would help to keep the lure moving more consistently oh well. The hole highest-up in the print orientation is where the leader should enter the lure.

Neither version uses screw-eyes for attaching the two treble hooks instead, I simply ran heavy fishing line through a path in the body to the two hooks and left a couple of inches in front of the lure as a leader. It may be useful to use a brim or raft, because the lure is quite tall and is supported by very little area. It prints without support sitting on it's tail end, as shown in the stl files. The improved version from May 12, 2015, is posted here in 3 sizes: 40mm, 65mm, and 80mm (as seen in gold, white, and blue in the last photo).

It could and probably should be finished with paint, etc., but I was curious to see if fish would hit the green-glowing plain lure (as seen in the photo taken in my darkened basement). I printed it in glow-in-the-dark PLA on my MakerGear M2 at 0.25mm and 40% fill that gives a nice approximation to neutral buoyancy. The original version of the lure (the red one in the last image) prints fairly well without support in the orientation shown, horizontal on its back, although a small portion of the back might be a little ragged that way.

Flat fish lure