Extinguish doubt
A winning attitude is not just saying I am a winner. You have to know you are the best at what you do, but do not confuse that with confidence. You can build yourself up and use techniques to make you believe you are the best, but their will always be doubt.
Doubt is extinguished by knowing more then your competition, by understanding your customers business deeper then your customers, and by working smarter then everyone else. The last point is where I am working to extinguish my doubt. Focus on procedure and techniques that allow you to respond faster to customer then anyone else. How are you erasing doubt from your mind on anything you work at?
Be an adviser an extension of their business. This is not handed to someone, respect the position you are in and care to learn about their business. Why did they start this to begin with? What is their passion? What is yours? Listen to their story, listen to their problems. Absorb before you act.
Do this and you can extinguish doubt, extinguish doubt and you can be the best, be the best and you are a winner.