I have a canon as well, (7d mk1), used to be big into photography, even entered some comp's.
I've had Dslr's for 6-7 years, but it was only last year when asked to take photo's for a friend's wedding (my 3rd wedding as "official" photographer) I rented a better lens (17-55mm f2.8) and was blown away by the improvement in quality. Even without any post-processing in photoshop, the quality was noticeably better.
If I was taking photo's more regularly I would def' buy that lens, it blew my 18-85mm f4.5-5.6 out of the water.
It doesn't matter too much how many mega-pixies you have, the biggest difference is found by putting quality glass in front of the sensor.
As for workshop photography, the things I try to achieve are;
Neutral and even lighting. I tend to use a flashgun bounced off the ceiling to give flat, even light. (then try to make sure that the white-balance is set so that all the photos have the same colour tint or lack of tint)
Make sure focus is on the the part you are wanting to highlight and not the background. Also have enough Depth of Field so all of what you want in focus is actually in focus (especially important with close up shots and Macro shots)
Use a bit of white card/paper to put the part on unless the "shot" is to show it being machined on Lathe/mill/machine.
Put something in the frame to show scale, and something that is fairly well-known worldwide, ie a Pencil, Mug.
Fill the frame or crop the photo so that the object fills the photo so that there's little wasted space. (especially important on forums)
That's all I can think of