Ahh, of course. Have you tried scanning photos at 600 dpi and then printing them out? The enlargement process might help out a bit with that. The other option, I suppose, would be to not use your eyes.
Yes, you have the time limits, the client's expectations, the omnipresent risk of making a mistake and having to start all over etc! And the most difficult of all, at least for me, is when the reference photo is out of focus, is too small, or sometimes just a very bad shot in general. Haha We have to work our magic and make it look better!