This is a short guide, how to improve checkout process, including some "do's and don'ts".
Keep it short
Simply nobody like to fill too much information, keep checkout form as short as possible, If it is not possible, then divide the form in few different steps. This will "chop" the process into bitesize and will make things more clear.
Include Alternative Payment Methods
Offering variety of payment methods and processors is essential, especially for International businesses. In many countries, Paypal isn't so popular, nor debit/credit cards can be used online. Adding alternative methods is a good strategy to increase sales.
You run multi-lingual shop, all items and important pages are translated into several languages. Did you forget to do the same on checkout process? Often I see shops loosing customers just because checkout page is in default language.
Analyze All Steps
Find out on which step customers are leaving the shopping cart. This is essential to know and this might be the only problem of your store checkout process. Additionally put youself into customers shoes, find out what you like and don't like when you try to proceed with test order.
One more good strategy is to check your top direct competitors, they might be doing something better than you.
Make Shopping Basked Visible
Have you ever tried to buy something, adding items in the cart and finding out that you can not discover the shopping cart to checkout? This is common problem with an obvious solution.
I've recently worked on a project where the management team decided that only logged in users can proceed to checkout. This is certainly OK, if it is absolutely necessary, though for that kind of business, it isn't. Give an option to checkout on registration or to checkout as guest.
Additionally collecting less information and explaining how this information will be used, will improve the checkout process. Many potential customers fear giving extra information.
Labels and Tooltips
Labels and tooltips are excellent practise for a good reason. Explaining the whole process will reduce uncertainty to minimum.
Continue to Optimize and Improve
Web development and content optimization is continues process. Do not limit the improvement and optimization process. Analyze website usage on regular basis.
If all these steps are followed, results will improve gradually. Many of these shopping cart checkout process tips also apply for creating custom forms of any kind.