Dunster is correct. What you DON'T want to do is sew your border fabric on, then trim it even. This will result in wavy borders. Attach borders as the others have described.

I lay a fabric border down the middle of my quilt. I pin one end and cut the other end to fit. I do the same across the middle. I do it again with the other two borders. I don't measure with a tape. Why have a middle man.

This is what I do. I find it gets me a more accurate piece than trying to measure it with a tape. I always cut them cross wise. I never have enough length to do it any other way.

Here is a really good blog with pictures explaining how to do it. http://frommycarolinahome.wordpress....nding-the-why/

this thread was posted an hour before yours http://www.quiltingboard.com/main-f1...s-t242291.html

Thanks for posting this link! I think it's shows the proof why borders should be measured, pinned, then sewed.

Nan - Indiana

Thank you for posting the link to my tutorial! I spent a lot of time to get the pictures right so it is understandable. Let me know if you still have questions, as I am always looking to improve understanding.
http://frommycarolinahome.wordpress....ders-tutorial/

I cut my borders a little (2") longer than needed. When I sew it on I just lay it on top and sew then trim. Only pin (or not even) about 10" in front of the needle. No puckers or waves because I don't have to stretch or scrunch it to fit a certain length! Works great for sewing on the first side of binding, too.

That is how I sew sashing to blocks.

It is important to measure three times, in the center and about 6inches (or the length of of the block) from the edge on either end and average for a correct measurement for borders. I always lay my quilt down flat to measure rather that hold it up in my hands because it is more accurate. You will most often be inaccurate in the measurement if you measure right at the edges because you cannot control the stretch of component parts. Someone mentioned she always had to do crosswise borders because she never had enough fabric left to do lengthwise borders. That can be solved by cutting the lengthwise borders first. If you need to piece them use a diagonal seam and match the pattern if that is appropriate such as large flowers or animals or other things that would be obvious if not matched. While ou may not consider the border as prominent part of the design you don't want them to be a distraction.