Do that by not being an asshole.

Give other people the impression that you value their contribution even if you disagree with it. Don’t walk over people to get what you want and don’t leverage the power you may have against others unless they are blatantly doing the same to you (in other words play politics only in self-defense….but when you do take no prisoners).

Why do all this?

Because as you progress in your industry and you grow a little older it will start getting harder to jump from company to company at will. Your network will also be progressing in their positions and have more influence and those networks (not online job ads or recruiters) will be doing most of the hiring decisions.

If you were an asshole when you worked with these people years ago will they pick up the phone and call you now, will they give that informal recommendation that is so important when people as their opinion about you?

I know a highly talented man in his early 50′s that has been unemployed for a year (with a wife and kids).

When you work with him he never compromises his position and will always push to make sure his chosen approach to an issue is the one taken. He will spend inordinate amounts of time brown-nosing to the bosses and will work all the hours god sends to make sure that if you disagree with him that your opinion is not listened to. He will also spend that time making sure that he exposes every flaw in his immediate superiors working habits to those same bosses as a way to move up the chain himself.

Now ask yourself why this man, at that stage in his career, is out of work? Why nobody from his over thirty years of working life has reached out to him to offer him a position?

That could be you if you are an asshole. It might never come back to haunt you if you are one, but ask yourself how you would fare being unemployed for over a year with no sign of work on the horizon.