If your borders are coming out crooked then your fabric isnt squared. I used to have this problem all of the time. It's a pain to have to square and my hardest problem was you lose some fabric but at least you aren't losing fabric because it's curvy. My one teacher only tears her borders; she says it's the easiest and you'll always get them straight.

I cut my borders lengthwise cuz I really don't like to have joining seams in borders. I have an 81" table that I lay the fabric out on, folded selvage to selvage. I slide a 24" cutting mat under the fabric along the edge I'm cutting and use my 24" ruler. If I need more than 81", I carefully slide the fabric down and continue the cut. Cutting that way, there's no risk of elbows from folds and I cut the two side/end borders at the same time.

I rip it.

I prefer to cut lenghtwise if I have enough fabric. Fold it so that it is squared up - no ripples in the fold line. Make your first cut (to cut off selvedges) a generous cut. Before you make another cut - pick up your first cut and check each fold line to make sure you don't have the dreaded V. If you do, re-fold.

Cut one piece at a time, check each piece for the dreaded V before you cut the next!!

And use a brand new rotary blade.

Rip it!

I use the rotary cutter and cut the whole length if I have the fabric, which I would if I bought it for the quilt.. I did a kit and it didn't have enough to do in one strip so had to piece.

I piece my borders. If you do a diagnal seam you can hardly see it.

Thanks for all the tips everyone! I definitely will follow them.

I tear my fabric usually 1/2" wider than I need..works perfect every time!