The best thing you can do for a Rancher who answers your question is to say thanks. Since everyone who answers questions is a volunteer, they get the satisfication of knowing they helped you.
It also shows that your question is resolved. Similarly, it helps to write the solution if you did something differently to fix the problem. That way others searching the forums can get a resolution.
And even if an answer doesn't solve your problem, even if it should totally miss the point - the best thing to do to motivate others to continue trying to help you is showing respect and gratitude for the investment of time that was put into dealing with your issue.