There are many web design companies out there, so to be able to compete and win clients you need to be offering a high level of service. When it comes to web design and programming, client testimonials are essential. Potential customers want to know that you have a portfolio of clients that are happy with the work you have done for them and may want to see working examples of websites you have created, so adding this as an area on your website should be a high priority.
Many web developers struggle to sell their services often because they do not explain the product / service to the client correctly, so making sure that you know how to speak to clients in a language they understand is vital. When quoting work, don’t be too greedy, if you can undercut competitors you may get the contract and even if you do not make a huge amount of money on the first phase, it may be that you get ongoing work from them afterwards.