Are you making a lonestar from a strip pieced method? Sounds like one I did that way. Anywho...here's my suggestions. If you can PRESS your strips to get them back to normal, starch the daylights out of them. What I tend to do when I have long strips with lots of seams to match is start it the middle of the strips I am matching. I also do as some others have suggested, placing a pin straight up/down through the middle of the seams both top and bottom fabrics and then, while holding that pin as straight as possible, put pins as close as possible to either side of it. Work your way to the ends from both sides of center of the strip. When working with angles, your ends are always going to have 'dog ears' of 1/4" so don't try to match up beginning with the ends. Hope this helps. Starch (and lots of it) is truly your best friend when it comes to bias edges.