http://msdn.microsoft.com/library/ee354180.aspx
Steps:
Designing a Service Contract
Implementing a WCF Service
- What instancing mode will be used?
- What concurrency mode will be used?
- Are transactions supported for this service type?
- Should the service join a particular synchronization context?
InstanceContextMode =>The default is PerSession which is typically not the desired setting.
Hosting a WCF Service
- How many endpoints will be exposed for the service type? What protocols will be supported?
- Will a metadata exchange endpoint be provided?
- Which service behaviors and endpoint behaviors will be configured?
- What features will be configured programmatically?
- What features will be configured declaratively?
- Will a custom and be useful to encapsulate common initialization features?
Generating Proxies
- How will collections and arrays be handled?
- Is a consistent object model desired to match the service implementation?
- How will exceptions and faulted channels be managed?
- Are there multithreading considerations?
- Is UI responsiveness a concern?