A key nugget we appreciated was:
2. Don’t fall in love with your requirements.
Documenting your own processes and creating a list of requirements before finding a consultant is a great thing to do. It will help save time and guide us in the right direction. Just don’t fall in love with the document. Use the requirements as a platform to start a conversation with your consultant and be open to making changes.
Consultants write up requirements all day, every day. Most users do this only when they are tasked with adding new functionality and providing guidance to consultants. Don't get me wrong, I love it when clients actually write up requirements, I just think they represent a starting point, not the finishing point. Good systems come from teams collaborating and having a conversation that involves probing, exploring options and prototyping.