Help the user trust you / your website, offer different payable options, inform user about the return polices etc..! This conversion rate is a measure of the number of potential customers that go on to buy from your website.
Try to get targeted traffic. It's possible that you can get better conversion if you can also get targeted traffic.
well it all depends on what you are selling...and are you getting targeted users to your website. Have you tried google ads?
Website trust and regular site visitors are hard to get.. though it's possible if you'll present your site professionally. Add a worth-reading web pages/content and use a good design
Depends on what kind of website. If its a blog, try to add banners and call to action such a "Click Here to xxx".
Make sure your price is good, design is well done, you look like a secure website, have an SSL certificate, your text is written well, you have a good refund policy and you have plenty of images for each product. Plus its worth using Google analytics to track your conversions, keep playing with different things until you crack the formulae! Good luck!!!