The keyword meta tag has been rendered all but obsolete due to spam abuse. As far as page titles go, search engines "read" left to right, so a typically good set up for a product page title looks like this:
relevant keyword | product name | your site name
I use the | symbol as a separator because it neatens up the line a little. Bear in mind that Google displays a maximum of 69 characters and spaces for the page title, so while you can put whatever you want in the title, make sure the most relevant, broad-interest stuff is targeted first.
While the keyword meta tag is all but useless, the description meta tag is worth fine-tuning. If this tag is not extant, search engines draw the decription of your page by best guessing from the main content (usually the first paragraph of course.) Up to 156 characters and spaces can be put in the description meta tag, allowing you to write concise descriptions of products (may be a little time consuming) product categories, service pages etc. I try to never leave these to default, except on sites where I have a huge number of products, because it's basically like a little classified ad showing up in a search engine and I want it to read well and draw in visitors.