when I had a corner bed in my previous TT, I used a plastic ruler to help tuck things in. I saw a slipcover tool in a catalog that they were selling for about 10 dollars and realized that a 50cent plastic ruler would do the same thing. It really helped tuck into those tight corners and saved my knuckles as I always seemed to scrub them trying to tuck in the back side. Now I have a set up similar to yours, except I am not quite as much of a perfectionist. If I get sheets, blanket fairly smooth, so that the comforter covers it, then I am happy. Use my pillows to cover area at head that doesn't get covered by comforter easily.