First of all, I think the presentation of your items is really well done...your bowcards, centers, FB site, all look really nice!
As for the twisted, make sure your loops are pulled to make a tall skinny X in the front and the back loops should look like an = sign. That is really the key along with a nice crease. It takes a lot of practice but there is a lot of advice on here...just look around! And I can help you if you need it