Make sure your research and all job market material suggest very strong and current computer and technical skills. (this doesn't mean blasting social media... most mid 20-30 year old economists I know do not have/use Twitter.) Personal websites may be where most of that shows up. I suppose another aspect is using/indicating you know the trendy econometrics and data mining techniques. And to be clear I am not saying do these to blend in... your age might actually be a characteristic you can use to stand out. You can (implicitly) suggest you have maturity and experience. It at the very least will help you get remembered post interviews. I am just saying when I see a jm candidate who appears to be older I may immediately be concerned that they could be lacking technology and econometric skills. Best of luck!
