In addition to what Dan told you, use your macro setting. Whenever I'm shooting those cool, close detail shots, the macro mode helps me ensure crisp shots.
Along with the tripod recommendation, I would add using your remote to trip the shutter. If you don't have a remote, use the camera's self timer or a cable release with an 'old fashioned'

camera. It really is essential that the camera not move at all.
Lastly, get some good 'props'. Even though they may or may not be visable or in focus in your shots, an interesting background really makes a difference in those 'glamour shots'. Just look at some of the sexy shots in Am. Handgunner and you'll see what I'm talking about.
Mark