It is all about relationships. From finding mentors early on, and then creating relationships with vendors, venues, clients, and even other photographers, which all pay dividends down the road.
The more you can communicate with your clients in advance, both on paper and verbally, the happier they will be at the end of the process. Building that relationship with your client helps to manage expectations, build confidence in your skills, and creates opportunities for referrals in the future.
There are a number of ways you can expand your services to assist in building the relationships with your clients over the long term.