One of my golden rules in quilting is Press... Press... Press! The other is square up! I press outward even with sashing. I know there is always the risk of a pleat and using a hot iron and going in a circular motion I can usually iron out a plete. Over the years I have become pretty good and not having a plete. Frankly I don't worry about a small plete if I am using a higher lofted batting. When I use W&N I find I have less issues because everything will lay just as it should. Plus I don't worry because once the quilt is washed it is less likely to show anyway. There are no quilt police here either.