The method to stay in constant enthusiasm and to keep others enthusiastic is to see specialities in others.
Projection: Many times while I am sincerely working towards my task, I find myself losing my enthusiasm. I also might find people not very happy with me or my work. I do make an attempt to understand their feelings but fail to do so. Such negative responses further reduce my enthusiasm.
Solution: I need to develop the art of looking at specialities in people. The more I am able to see their positive qualities, the more I am able to relate to them with that speciality. This encourages the other person further to use that speciality. This will naturally keep me constantly enthusiastic.