I have a border stripe fabric that is crooked. I'm hoping I can straighten it out enough to successfully miter the corners. I've already cut it into strips, but they are very curved (think smiley - they curve up as you go to the edges). I haven't blocked anything before and wondered if this would help. How do I do it? Do I cut the selvedges off first? Any tips would be greatly appreciated.

After fabric is washed, the selvedges do want to distort the edges.
Cut them off and see if that helps :D:D:D

I'll try that. Thanks. :)

Great advice Amma! Thank you.

Once I cut WOF strips, I squared them up based on the stripes within the pattern and ended up cutting off an odd angle piece on each side. Whatever works! I was a little concerned because I was mitering, but it came out great.

Top has been done, but won't get quilted for a while. I wasn't a fan of browns before, but really like them.

Oh, for those interested, this is a simple D9P pattern. I used a fabric panel with various safari cats and put those in 2 opposite corners of the 9 patch.