Not sure about your particular wrinkling issue, but several years ago I made an Ann Ladbury trouser block. I have used it in conjunction with any trouser pattern I have liked ever since. What I have found is that the distance from the crotch point to the side seam on the patterns is way too long for me. I have a fairly average sized bum, neither too small or, surprisingly, too big. The pattern makers seem to assume, however, that we all have very big bums. My trouser block has turned out to be one of the best things I have ever done.