It's simple! Just go here http://www.girlsaskguys.com/contact and let the admins know that you would like one of your questions featured. In the drop down box, select "redeem xper." Then, in the details box, specify that you would like to have a question featured and include a link to whichever question you want to be featured. Just remember, it costs 500 xper points to feature a question and any sexuality related questions cannot be featured.
You can get there by clicking "Contact" (bottom of all G@G pages) http://www.girlsaskguys.com/contact - or you can click "Redeem Points" from the My Xper page of your profile. Clicking "Redeem Points" is a tad quicker, because the other way has one extra step (selecting Redeem Xper from the Regarding drop down menu). Include the link to the question you'd like us to feature (making sure it's NOT a sexuality question) and we'll send you a message once we've featured it and taken the 500 Xper points.
If you don't hear from us, don't worry - it's because there are questions in line before yours. They're simply featured in order of request, so it can take some time to be featured when we've gotten more requests.