It isn't work that makes you tired, it's your mental attitude.
When you face a problem, solve it then and there if you have the facts necessary to make a decision. Don't keep putting off decisions.
Do the very best you can.
Give the other person a fine reputation to live up to.
If you want to gather honey, don't kick over the beehive.
The unvarnished truth is that almost all the people you meet feel themselves superior to you in some way, and a sure way to their hearts is to let them realize in some subtle way that you recognize their importance, and recognize it sincerely.