Always look for an Authorized Tamron USA dealer. See Why -->
While your main subject is of greatest importance, being mindful of the entire image leads to better composition.
Al Gilens uses the 18-200 in this article on theatre photography.
D.J. LaDez uses the 28-75/2.8 in this article on basic portrait lighting.
David Maynard uses the 28-75 to demonstrate basic background lighting.
David Maynard uses the 180 in giving tips on lighting for macro.
Bart Stevens uses a few different lenses in this portrait article.