Pool training for open water

I have been doing open water for almost lucky number 13 years, and I think I have finally exhausted every possible way to go back and forth across a stupid pool! I get out in the open as much as I can, but the bulk of my training is still in the pool. I train alone and am self coached. I have done most of the various Masters and other published workouts, modified them to better suit distance training, called to mind old "favorite" workouts, made stuff up...But I am getting really bored! My typical workout is 6000 yards consisting of 1000yd warm up, 500yd kicking interspersed, and 3 1500s of whatever I choose (varying strokes, paces, ladders, pyramids, odd number lengths to finish on opposite sides of the pool for variety...). On the one hand this works for me in the sense that I cover alot of distance, am able to do plenty of open water swims, I stay injury free (shouldn't have said that out loud), manage my weight...On the other hand...I don't want to get stuck in the "garbage yardage" thing, sometimes I feel like I have no idea what I'm doing, and I feel like I am missing opportunities to get better. Any suggestions for what kind of workouts to do in the pool when my main goals are maintaining fitness and doing open water events in the 2-4 mile (and maybe beyond) range.