I am new at quilting. I have put together some blocks and sashing, ready for the border. Do I have to square off what is already done before adding the border? It seems that I have read about this somewhere????

I would square off before adding the border. It seems to work better that way.

It will be easier to get the border on straight if you are working on a square (or rectangle).

I square it up at this point, unless it means cutting off points or key design elements. If it will? I would add a wider plain border and then square it up :D:D:D

Me too!

Thanks all for the tip.

This is the way I do it too. I cut my border about 1/2 inch wider than I really want it. I will even up the sides, but not square the top. Measure in 3 places across the top, average them, cut the border that length and attach. Then after it is quilted I square up the quilt. If the border ends up being a bit wider on one end, no one notices. Also if the fabric creeps around some while being quilted it doesn't matter as much.