1. You don't wait to be asked.
Instead of waiting to be told what to do, you take action. If you don't know exactly what to do, you do what you think is best and then take responsibility. You're proactive and willing to take risks. It's more important to you to contribute than to wait for step-by-step instructions.
2. You don't gossip.
Regardless of how you feel about your boss or coworkers, you keep your opinion to yourself at work. If you need to vent or process, you do so with people outside the office. If you have a real issue with someone at your job (including your manager), you address it with them directly. You don't gossip; you communicate.
3. You do what you say you will.
You send the email you said you'd send. You follow up with the client you said you'd run point on. You meet deadlines.
If you don't have the bandwidth for a project, you don't take it on. You have a strong sense of what you can do in what timeframe, and you stand by that. You're comfortable saying no because you know that leads to the bigger "yes" - integrity.
4. You give value.
When someone on your team does well, you tell them so. You're vocal in your support of both of coworkers and superiors, and genuinely excited when someone else succeeds. People want to work with you because they feel uplifted being around you. You're collaborative, not competitive.
5. You offer proposals, not suggestions.
Instead of just criticizing or brainstorming, you give concrete alternatives. You don't force your opinion, but rather offer well-researched proposals about what you think should be done. You have a sense of the overall scope of what a change would entail (beyond just your department) and how you can contribute. You're committed to overall success of your organization, not just your own advancement.
Being exceptional at work isn't something you're born with - it's something you grow into. You begin by taking stock and then taking action.
It's never too late to start standing out.