I lived in Lewisville back when I bought by boat 10 years ago. I fished that lake all the time; that's were I learned to catch catfish.
In my personal opinion the best bait for juglines on LL is fresh dead shad. Hands down.
You can catch shad year round in the cut in the old dam, between old Lake Dallas and LL.
The best spot I had found for blues was on the southwest side of the lake near the dam. There are several sandy points that jut out into the lake toward the spillway. I used to set out 10-20 jugs, move back about 200 yards and R&R fish while the jugs would soak.
Hope this helps. I remember learning to catch catfish on that lake and all the damn good times I had. I learned a lot from old salt on the Whisker Kitty forum back then.
Anyhow, good luck. Post some pics!
Class of 2014, Oceanography, Chemistry
U.S. Army E5 ret, OIF 2004, OEF 2008