[galladanb]

boy wonder, greetings from Tenn...

My 2 cents worth...

You can use a steamer on the wrinkles and then use some method of
tightening on the drop horzintally, I use six total, 3 per side...

Also, your subject needs to be 5 or more feet from the drop for shallow
DOF to mininmize backdrop wrinkling and sharpness...

I might also suggest that you lower the power output of the AB's so that
you can open up yourapeture for even less DOF! It works for me most of the time.

Of course, you can always use PS masking and Guassian blur in post processing,
gives a lot of extra control...