I do the sides first and then the top and bottom for no other reason than I like the way it looks. I piece my borders so it doesn't make any difference with the amount of material I use. There is really no right or wrong way but rather the way you like.

How many borders do you want?

I like 3.
1.The inner border is the same as the background fabric and is about 3-4 inches wide.
2. The middle border is the framing border and is the darkest color used in the quilt. Cut about 2 inches makes a 1 1/2 border.
3. The outer border can be quite varied. It can have piecing in it or be plain or be scalloped. I like a medium to dark, but not as dark as the framing border.

When I put them on..(Now this is just my opinion and there is no Gospel here), I like to alternate the sequence.

Inner border put on sides first, then framing border top and bottom first, then outer one sides first. If you do not do this, then your corners are weaker, (I think). By alternating you don't get the stacked effect.

Marcia

I also put my sides on first then the top and bottom. I just like the finished look better.

I have found, over the years, that if I have a limited amount of my border fabric, I do better putting on the long sides first. If I have a lot of fabric, it does not seem to matter.

I've never thought about it until I read your question. There's a different look one gets if the sides go first or the top and bottom go first. If I want the quilt to appear visually longer then I do the top and bottom first so that the sides are one long length. Sometimes I do top, side, bottom, side. If I have enough fabric then I miter the borders and then it doesn't matter which is sewn on first.

If you miter your corners it doesn't make a bit of difference.

[ATTACH=CONFIG]591356[/ATTACH]Here is a pic of the corner of a three bordered quilt. The inner border is the same as the background fabric, then the darkest framing border and then an outside border. They were cut 3 1/2; 2 1/2 and 6 inches. It's just what I had and I like to make queen sized quilts. I hope you can see that the sequence of sewing them on looks like a brick corner, interlocking. Marcia

It "seams" that the sides have won. Thanks for the advice. As I said, this was just more of a curiosity question than anything. Now, when I think about it, I do my sides first.

I never thought about that before, but it makes sense.

And thanks, Battle Axe, for your explanation of the 3 corner theory. That makes sense to me too.

I always do the sides first and then the top. I just like that look best.