Once you find the right freelancers for the project, make sure you make them feel like a key part of the team, and keep them happy. It's better to put in the effort to have a good relationship with a single freelancer than to have a revolving door of professionals working with you.
1. Remember, these people know how to network. Once you've selected someone, build a working relationship with them that the person would be excited to keep. Next time you have a need for a freelancer, your trusted hire will be more open to the opportunity if you've enjoyed working together in the past. At the very least, the freelancer will be happy to pass word of your project along to others. This part is pretty simple: Follow the golden rule. Treat freelancers the same way you would treat your full-time employees and the same way you would want to be treated.
2. Be clear about tasks and work arrangements. Detail working hours, responsibilities and logistics from the start. Do you anticipate 40-hour work weeks? Can your freelancer work from home? Is there travel required? Is he or she reporting to, or helping to lead, a team? Once your expectations are aligned, it is less likely that either party will disappoint.
3. Position freelancers for success. Recognize your freelancer as an expert from the start. Give the person the authority and reputation needed to be taken seriously by internal and client teams. The best UXers will feel positive pressure from your kind words and will work to live up to the hype.
4. Share the best projects. Don't keep all the best stuff for yourself and your full-time staff. Your freelancers will appreciate interesting work and will be excited about getting to think about worthwhile design problems.