Here's how I fix a scant seam or two (as I had a couple of horribly scant seams on the triple framed pinwheel I made in this post). Cut a strip of fusible interfacing about 1/2" wide and the length of your scant seam. Iron it so it sits right on top of the seam on the wrong side.
Now flip to the right side and sew a run of tiny stitches (I set my machine to "1" length) along the edge of the seam - about a thread or two away from the seam on each side in threads as close to the colours of the fabrics as possible. These lines of stitches are almost invisible partly because they are the same colour as the fabric and partly because they are so small. And VOILA, your dodgy scant seam is reinforced.
And, by the way, has anyone had any problems reading the blog in the new font - I've had one person saying it's harder to read in this font and I wonder if that's just one person or affecting a lot of you?