Check your site in all of the different browsers. This is because your website may look a certain way to you in your browser, but will look very different in another browser. Research the different browsers that are popular and design your site accordingly. You should also check your website from a variety of different computers to see how it looks as well.
Always give viewers the option to cancel a current action. For example, put a "clear" button on a form, an unsubscribe link on all newsletters and a "cancel" button on orders. Not allowing customers to cancel actions that they do not want to follow through with is unfair, and it is forceful, which may prevent those visitors from returning to your site or making purchases from you in the future.
Always mark files that must be opened in an external program with an icon. Many sites host PDF files, and less commonly, DOC files, that must be opened in Foxit Reader and Microsoft Word/OpenOffice, respectively. These files should be marked with an icon representing the file type, and a link to download the appropriate viewer if the user does not have it.
Don't force users to install strange BHOs. Many tech-savvy users won't do it. Common offenders include unusual video players, image viewers, and platforms for interactive games. For most standard use cases, there is a trusted plugin, such as Windows Media Player or even Flash) that will do what you want without driving away https://wordpress.org/themes/ not interesting, won't captivate its audience. A website that uses fun, but non-relative information, will captivate the wrong audience. Both methods equal profits that you are losing.
http://www.youtube.com/watch?v=FRJV_TSvti0
