This is just a small warning to you all: Study and research what you are going to shoot, just to make sure everything is done properly. This will make your images more saleable!
Here is an example:
I have played clarinet (a musical instrument) for a long time ago. Some time ago I searched for clarinet images to find gaps in collections that I was planning to fill. I got surprised how many crappy shots there were, images where the instrument and/or the action looked totally silly (unintentionally). Here are some examples (from 323 results at Getty's):
Hands (left/right) are the wrong way:
http://www.gettyimages.com/detail/104821717/OJO-Imageshttp://www.gettyimages.com/detail/108313623/Vettahttp://www.gettyimages.com/detail/84049748/Photographers-Choicehttp://www.gettyimages.com/detail/78722497/FuseWhat are they doing?
http://www.gettyimages.fi/detail/96389322/Culturahttp://www.gettyimages.fi/detail/88798525/UpperCut-ImagesYou can't play clarinet wearing gloves:
http://www.gettyimages.com/detail/LS000837/Photodischttp://www.gettyimages.com/detail/71078879/StockbyteI have no idea how they have managed to assemble the instrument so wrong
http://www.gettyimages.com/detail/99276468/Tetra-imageshttp://www.gettyimages.com/detail/57443016/StockbyteThis is a mirror image:
http://www.gettyimages.com/detail/87854228/Dorling-KindersleyThe moral of the story: Spend some time researching your subject and/or get someone that is a specialist on the subject to be a "technical advisor". Otherwise the images may look silly to the trained eye.
Do you have more examples on other subjects?