Show that you are getting things done
I have seen a good many developers who get great things done, which go completely unnoticed by their higher-ups. In regards to marketing oneself, its important for a developer to develop "The art of subtly conveying his accomplishments", as and when the situation presents itself. It is a constant process which should be actively sought out and carefully without appearing to be a show off.
When it matters, prove that you actually have the skills
The emphasis is on when. It depends on a lot of factors, which you must determine based on your situation. Trying to do this too often will actually be counterproductive to you and your team-office dynamic.
Mentor only when really required
This would save your productive time and theirs thereby increase the value of mentoring.
Increase Your professional network
This would work on so many levels. For example, your increased network might be the key to your organization filling a key position with a good candidate from your valuable referral.
Show genuine interest in building relations with colleagues
People can easily spot a fake-poser. When the correct opportunity-need arises, going out of your way to assist a colleague with them being actively aware of your special-extra efforts.
Increase your online technical portfolio
This is a primary area which needs to be regularly worked upon keeping up with the current market trends, popular requirements: developer blogs, SO reputation, online apps,code samples,techical forums,articles.You know it,The whole shebang.
Making the right people passively aware (emphasis on passively) of this. Who encompass higher-ups, network, peer group, potential future prospects.
Evaluate and accept opportunities with forethought
Don't hesitate in putting effort
Lastly, but most importantly, remember
The golden, time tested facts of How to win Friends and influence people apply to ALL domains.