When you're being commended by your boss or a team member for your hard work on a project, don't blow off the compliment. The time and effort you put into your work isn't "nothing," so don't say it was. Instead, take the compliment, but be sure to state how glad you are that your hard work paid off. Something like, "That's great to hear. I'm really happy the hard work paid off on this, and we have some real results to show for it." A statement like that is appropriate and puts the focus on your efforts without coming across as cocky.
The real trick is to keep track of all of the praise, whether it's in emails, meetings, or in reports. This is the real fuel for launching your campaign to the top. Keep copies of email exchanges that commend your hard work, whether it's from clients, teammates, or superiors. These records will be very useful when you're meeting with a manager or higher-up to discuss a raise or promotion because this is the real evidence of success in the work you do. It's easy to turn down someone who doesn't have the facts to back up their performance — your bosses may not remember every single one of the great things you do, but recording each of your small successes only gives solid evidence that you're ready to take on bigger projects. So, don't throw your compliments or kudos out the window, take note, save 'em up and use them to your advantage where it counts.