Research
Most galleries and independent curators have a definite style or interest in specific types of artwork they are interested in, and it is a good idea to research this carefully to save time and money and avoid cutting off avenues of future opportunity. Call them up or visit them and ask a member of their staff how they prefer to receive information and images.
This site contains extensive listings of artist-led spaces, small and large crafts and visual arts venues as well as medium-specific venues which would make an excellent place to begin your own research.