We came across this valuable summary on e-consultancy about current techniques & approaches to improving conversions.

Read the whole article, but here's a summary:

1. Have a FREE delivery proposition
2. Provide a USP bar in your site-wide header
3. Quick access to both new in and sale items from the primary navigation
4. Have a view all link with a variety of useful features
5. Encourage and use customer ratings and reviews
6. Provide multiple photos showing products in different use cases
7. Make your payment options transparent on the shopping basket
8. Provide visible security assurances and trustworthy logos during checkout
9. Enclose your checkout to focus visitors attention and maintain buying momentum, and provide easy access to customer service details

The article is also full of quick hints & tips about how to do this.