Our loan officer did a great job making the process administratively easy, despite the fact that I was in 4 or 5 different cities (business travel) during the process.
View this 7 minute video which explains the connection between interest rates & mortgage backed securities. For those who monitor interest rates - this video highlights why one cannot rely on the media! It also describes how the Federal Reserve works - and what they are doing to keep interest rates low.
Ultimately anyone "interest rate shopping" or looking for home financing must work with a Mortgage Professional who understands the importance of not just watching mortgage backed securities, but gives great guidance.