trigurl - why don't you try some of these. I'm swimming between 1500 - 3000 meters at a time. I'm not sure what distance you're going right now, but you can find something in here to help, hopefully.

1750 meters (250 wu, 250 x 5, 250 cd) 30 second rest between each, steady efficient pace

2000 meters (250 wu, 100, 200, 300, 400, 500, 250 cd ) 30 second rest between each - steady efficient pace

2300 meters (250 wu, 150, 300, 450, 450, 300, 150, 250 cd) 30 second rest between each - steady efficient pace

2500 meters (250 wu, 500, 250, 500, 250, 500, 250 cd) 30 second rest between each, steady efficient pace

2800 meters (250 wu, 250, 500, 800, 500, 250, 250 cd) 1 minute rest between each - steady efficient pace

I am trying to focus on form mostly during the drills. I also take a swim class once per week where we focus mainly on positioning in the water.