|There are many fabircs whose right or outside is the same as the wrong or inside. To avoid having two of the same sleeve or some similar diasters, consider using blue painters tape.
When I'm cutting out a fabric that I know will make me think, I add a piece of blue painters tape to the wrong side. As a result, when I'm sewing, I just need to look for the blue tape to know I have the pieces properly put together. I need to see blue on both sides and then I'm safe to sew. Very helpful late at night.
This tip is especially useful when sewing multiple garments of the same pattern. When sewing pants for my Mom, I used to put the tape on the front and back pieces using horizontal and verticcal to distinguish them. It reduced my margin of error significantly and allowed me to speed right along with 3-4 pairs of elastic waist pants.
Blue painters tape leaves no residue (that"i've experienced to date) but stays in place as needed.
Another thing I have used it for was to mark the direction of a silk and another sheer fabric where I had 18 yards and needed to cut it in half and seam the two pieces together. In both instances, the light hit the weave in such a way that you had to treat it as if there were a nap. I did not want to use pins for fear of marking the fabric and the possibility of the pins coming out and then it would be a guessing game. A couple small squares of blue tape strategically placed before cutting solved the problem.