You can misplace them here and there but it's always a good idea to study your sewing board before sewing the patches together and after. It's easy to see a misplaced patch and it can be fixed right away. I have misplaced two in all this sewing, so that's not bad and I caught it before sewing. You can also check my cross quilt as I have done that the same way and it worked for me.
http://www.quiltingboard.com/picture...t220202-5.html