Salespeople must work hard to keep negativity in check. There's no denying the fact that cold calling, prospecting, and facing daily rejection has a way of piling up on even the best salespeople. But there are ways you can combat the urge to sink into a negative slump. Go for a walk, call someone who always cheers you up, or do something nice for someone in need. Never allow thoughts of self-doubt and insecurity to take root in your mind.