I would also add ...

Use <H1>Headers</H1>

Especially if selling a product. Find a way to get the products name into a header tag on the page. Above the description works well.

Work in an H2 over a new paragraph using your products keywords if possible.

If you're selling products and filling in the meta keywords field ...

stawp!

You're only giving your competitors your list of targeted keywords, it's not helping your search ranking at all.

Sign up for Google Webmaster Tools and use their Data Highlighter area to add your product information.

Tip : It's a good idea to use the Crawl > Fetch as Google option before running the Data Highlighter. You can specify individual pages as well. This way Google has already fetched your page information so that it can be used with the Data Highlighter.

This way when your product is displayed against your competitors, you will show extra information, like price and customer reviews. It really makes your site stand out versus others who are not utilizing this feature.