I've heard some say that they like certain sketch artists because they include size measurements of the papers with the sketch. Unfortunately, I don't have the time to do all of that with teaching full time during the school year and then doing training sessions in the summer. So, I come up with some other ideas that might help.
I make all my sketches on graph paper. So I could also post my drawing (ignore the "X" on the pic as I always cross them out when I have created them on the computer), although sometimes I make changes to it as it goes to a digital format. For this particular sketch, I moved the pictures apart a little bit.
#1 - Sketch
I could also put this grid over the top of it.
#2 - Grid Overlay
Or I can put a grid behind it.
#3 - 1/4 in grid
#4 - 1 in grid
I would also ALWAYS include the original digital sketch, but would one of these other options help you out when using the sketch? Please post what number(s) you would like to see whenever a sketch is posted.