Nice! Perfect focus and very sharp
Getting good contrast in the lighting can be tricky - I usually aim to get the lighting ratios (e.g. difference between directly lit and shadow areas) right in camera because it takes forever to fix in post.
The flash lighting was a bit harsh - did you have anything to diffuse it? I've found that having something as simple as an A4 sheet of paper between the flash (zoomed wide if possible) and subject will do wonders, possibly a second sheet nearby as a reflector to provide fill lighting.
Re exposure: with my dSLR I always shoot RAW and plan on (at least minimal) post processing, so I normally follow the "expose to the right" approach using the histogram. Basically, I expose the scene as far right on the histogram as I can without clipping too much (my RAW converter seems to recover about 2/3 - 1 stop of clipping quite well). In Lightroom/Photoshop, I "underexpose" the shot to a proper exposure and then apply levels/contrast/colour adjustments as desired.
This approach seems to work really well for me - the photos look very rich and "real" on wide gamut monitors and large prints.