Instead of doing SITD, I use a rounded, meandering stitch that is one of the programmed stitches on my machine. I do it over the seam so you get to see the thread and you also don't have to worry about your lines being "straight". It also "strengthens" the seam area because it covers the seam, so no chance of the seam coming apart.
(Sometimes my seams are less than 1/4"...just because I'm trying to make the block square and I might be a thread or two short on one particular piece. I know, I know...I'm probably the only one with this problem!)