1) Be focused, concise and snappy
Your mobile site shouldn't try to take on all the content of your main website. The point of having a mobile website is that visitors, seeking for information and reference in your website using smart phones, can easily find the most essential information about your business and your offering. Going through a normal webpage may require several scrolls and pinch zooming. Saving your visitors from sipping through too much information on their phone pays off well. So, planning out how to simplify your content for your mobile site and how to re-focus its marketing message is essential for the success of the mobile site.
2) Provide very straightforward and super intuitive navigation
If navigation is important for the main website, it is super important for the mobile website. Statistics show that visitors using mobile devices have even shorter fuse than non-mobile visitors. If the information the visitor is expecting on the given mobile page is not apparent, then the visitor will leave within a course of couple of seconds.
3) Go light with the images
People don't expect to see high resolution high quality images on their mobile phones. The goal of the mobile site is to provide fast reference!
4) Offer your mobile visitors the choice of visiting your main site as well
Make sure that your visitors can easily access your main website from any of your mobile web-pages should they decide to see your website in full details. Think of your mobile site as a tool, which - by providing focused & well crafted information - convinces your visitors to either contact your right away or to switch to your main site.
5) Pay attention to how the mobile and the main sites link together
Make sure that your mobile and main websites are set up in a proper structure. Without a proper structure, visitors using a mobile device may get into an endless loop as they want to switch from the mobile to the main website. Special attention needs to be paid when setting up the structure so search engines understand the purpose of your mobile site. Otherwise is easy for the search engines to mistaken your mobile site for a spamming attempt.