Just my little WIP for a 599 GTB
It looks like you are off to a good start, keep it up. A few suggestions, check for bumps, I am not sure if it is your lighting setup or bumps, so be sure to check it. Because of the last note and to help keep you concentrated, better motivated, and doing it better, don’t worry about rendering right now. Once and a while you can do a quick render to make sure things aren’t horribly off, but stick with modelling until you are finished. Be sure to take your time and do it well, no excuses. Be sure to check often though with a matcap or something to help find bumps.
Here are a few spots to check out. Would you be able to post a couple screenshots with a matcap or something better to show off the model? That would help us find sports in your modelling to critique.
What material would you recommend for the matcap
I’d use the matcap option first, and switch around between all of the glossy ones. If that doesn’t work, and just in general for not using a matcap have a viewport shader with a bit of contrast between the regular and specular colors. Play with the hardness to see what helps you the best.