A simple fact of work-life is that if you want to be paid more, you need to deliver more. And the only way to achieve “more” is to know what your company and boss expect you to deliver in the first place.
Make an effort to do something kind for someone every day. Help out with a project, offer a compliment, give someone the better parking space, remember a birthday, stay late to cover for a co-worker with a sick child, and so forth.
In addition to keeping you toned and at an appropriate weight (both of which make you more attractive), working out generally makes you happier, which can have significant benefits in your “being likable” efforts.