If you have many people that abandon their shopping cart in your online store, there is a number of reasons for this. One could be the fact on how people make purchase decisions. Initially they start from emotional of point and transition logical after sometime. For someone who starts the checkout time and effort to complete data will have to be at minimum level. If you remove all the elements that cause distraction you can have a smooth checkout process this will lead to higher conversion rates in your e-commerce store.
Clear checkout page from distractions
In modern theme design, you can see frequently long footers with many menus and a newsletter subscription. In checkout page there is not need for such big footers with a lot of info data and newsletter form. There are many reasons this, for example a message in the newsletter copy, like "subscribe now you will have 5% discount on your first order" could cause a general disruption.
Final total price
A clear view on final price is important because every potential buyer would know precisly what he will pay. Despite the choice of payment method, shipping destination or discount codes to calculate total price accurately is very important. There are many cases that somebody use a coupon code and there is no proper integration with the payment method so when is redirected to payment provider in screen appears the toal price of cart without the discount. This pure quality integrations can prevent many users from completely the purchase and also lowers trust on the online store.
Customer support and refund policy
When you have a clear defined return and refund policy this could make more comfortable users to make purchases in online stores. Specially items like clothes that you cannot have a clear idea on quality from a picture. For example someone could order a jacket that could have a good quality, but was not suitable for winter, it has to be possible to return and taking your money back easily and without problems. Also in e-commerce business refund policy is obligatory by local laws.
Multiple payment methods
Having a wide variety of payment methods do not allow customers to think twice on how will pay. A wide range of payment methods such as credit card, cash on delivery, paypal, wire transfer is important. So do let customers think twice about this, if the user is already a customer in checkout page, he should see first, in the list of payment methods, his preferred one. A good personalized experience could remove a lot of friction and obstacles.