This post isn't really about money. But I'm going to talk about it to make a point.
Years ago I was the writer on a certain campaign. We shot five spots with a man who was (probably still is) one of the best directors in the industry. The ideas were on strategy so the client loved them. The spots were creative so the agency loved them. And the production was pretty high-end with a lot of props and visual effects so they were fun spots for everyone to make.
When we wrapped, my producer turned to me and said, "Congratulations. You just doubled your salary." I asked what he meant, and he said, "Put this stuff on your reel, and wherever you go next, expect twice as much as you're getting now." This was before anything was even edited. We had barely started to listen to music for the spots.
But that's pretty much what happened. The spots were better than anything I had on my reel at the time, and they got some national recognition. So when I took another job a few years later, I was able to ask for almost twice as much.
(Let me pause to say that you should never take a job for money. Never. It can be a factor. It can be something you earn. But never let it be your motivation. Take a job you don't like and no number on your paycheck can comfort you if you're waking up every day thinking, "Crap. I have to go to work.")
But this post isn't about doubling your money. It's about putting yourself in a position to do the kind of work that you and your agency can be proud of. Money is just a convenient metric for determining the value of your work.
I was very lucky to be the writer on that campaign. I was lucky to be at an agency that championed great work, even when the clients didn't. I was lucky to have a partner who wanted to make the work better, and a creative director who knew how to make it better. I was lucky to be on this particular assignment because for every great campaign they let us do, we had to produce eight terrible ones. They weren't Nike. So getting this particular assignment was just dumb luck. And that sometimes happens, too.
But if you're not at that kind of agency, with that kind of partner, and that kind of creative director, it makes it more difficult to double your salary. To say nothing of doing great work.
So give yourself as many opportunities to luck out as you can.