Juniors: Make friends with the account people.

I'm serious.

The better your relationship with the account managers/executives/supervisors whatever your agency calls them, the harder they work for you.

The less you bitch about the client and the more you listen to them bitch about the client, the harder they work for you.

The more you show a willingness to honestly listen to their feedback and make client changes without complain, the harder they work for you.

It's about building trust.  You show that you trust them and they'll trust you.

Because nothing helps sell good work like having an account VP trust that your idea is the best idea, and going to bat with the client for it.

But like I said earlier. Be worthy of that trust, because nothing kills good work as quickly as an aggravated account executive who thinks you're a lazy diva/divo.