Put the right buzzwords in the first sentence of each paragraph of your resume to make sure it gets read. Showcase your skills and experience that meet the client's ultimate objective. Cram for a job. Study new material that interests the client so you can be familiar with the technology and details of each project. Demo the interview.
Role playing greatly increases the success of an interview.
It also better prepares you for inevitable bumps. Write down scripts. Take the time to guess at the client's first line of questions, then write out scripts to answer them. The process of writing out the answers engraves the answers in your mind. Once in the interview they'll flow out freely and give you a significant air of confidence.