I made a start on joining the blocks last night, but realised one thing really quickly. 

This will only work with blocks that are the correct measurement!  I'm a 'fudgey' sort of quilter; I aim for perfection, and when it doesn't happen I shrug and fudge the results into a passable top.  The key is to aim for perfect in the first place though; if I just throw things together at every stage, it all adds up to grief in the final assembly and quilting.

The blocks I've already made are somewhat, um, individual in their measurements. 

They HAVE to measure 9" from edge to edge, and 11"  from corner square to corner square.

 Lots of them don't.

Out of 14 there are maybe 6 that I can use with this setting method.  There is just no room to manouvre with a set-in seam; there's no wiggle room left.  So the blocks that just won't do will go into another project, and when I start constructing the next lot of blocks I will take a lot more care to see that they come out right.

I think I swapped sewing machines halfway through these blocks, and also changed the method of piecing them, when I realised they were going askew.  As much as I liked the way I started with, sort of sewing in rows throughout the block, it just didn't stay nice and square. 

Starting with a modified nine-patch and adding pieced corners results in a much more accurate finished measurement.

It's a good thing I'm in the mood to be persnickety, and take my time over these blocks; sometimes I just want to quickly arrive at the finished top, and other times I want to concentrate on enjoying every seam and patch.  This is one of those quilts.