"He who marches out of step hears another drum." ~ Ken Kesey
Looks good for the first one. I think it can use some tweaks (depending on what the original looks like).From the looks of this print, I would say that I would prefer to include some color in the shadow areas. It looks as if the whites fade to black and the shadows are the black shirt. This makes it a tad blotchy and "dark color" always works best for shadows versus using shirt color or straight black as the darker parts. Black fading into small %'s of color up to the solid flesh area such as the ladies arm.
Those look more "toned" than the original picture. Looks pretty good for a first time Sim. Congrats.