I recently made a disappearing pin wheel quilt as per Jenny of MSQ. Had the whole quilt together with backing, quilted in the ditch to stabilise then looked at it to work out my fmq design. I could not work out why my design would not fit until I realised that one square of a corner block was around the wrong way!! My husband said to just leave it but I couldn't so there is one hand sewn piece in my quilt and only I know which one it is.
It is so easy to do, but hopefully we learn as we go. Your quilt will be lovely when your'e done!