I'm working on my trying to finish the first quilt that i started. Its a Liberty Log Cabin. I have a question about squaring the blocks. Is it better to do it after adding each 'leg'? Or wait until all of the pieces are attached and then square it?

My thinking: if I square it after each leg, then i'll only be cutting a little off each one; if i wait to do it until the end, then it is possible that all of my blocks will have an outside piece that is thinner than the other pieces.

Any hints?

Good question as I have the same problem!

I squared each of my blocks as I went along when I did my Log cabin wall hanging. I was afraid of having to trim too much if I waited to the end. Plus if each block is squared it shouldn't need much when put together.

I use a square and keep each round straight, but still wait until my block is done to square off. I think all my log cabins have been scrappy and yes I have one or two that have a skinny edge. Being scrappy it does not matter and I don't know if anyone other than a quilter would even notice.

I've only done one small log cabin project - and I did it by paper-piecing - so it was all true & squared up when I did the final outside trim.

You could cut the last pieces a bit larger then trim down as the last thing.

I square as I go along, but have done it at the end. Cutting and sewing 1/4" seam very important.

I don't square up at all. I just "block" the blocks as they are finished (if they need it, which they usually don't). I wouldn't dream of cutting off fabric to square up a block.

Sharon Schamber has some videos on Youtube that show how to "true" blocks with spray starch and an iron.

If you don't square as you go along, any unevenness in seams gets magnified with each added round. Something that could be trimmed and squared to be unnoticable becomes a mistake that your eye will always be drawn to.
If you only want to square your blocks in the end, I would at least measure them halfway through to see how accurate the measuring and sewing was, and then decide whether adjustments need to be made. Some layouts (barn raising) are great for hiding mistakes, so there are other options. Log cabins are one of the most forgiving quilts, great for beginners and oldtimers alike.

I square as I go. It seems to work best for me.