The best way to receive as many messages as possible is to make sure that your profile is 100% complete.
Make sure that you re-read your narratives to make sure that they make sense, that your spelling and grammar are accurate, and that you aren't using abbreviations that may not be familiar to everyone. You should write your profile in the same way that you would write a cover letter for a job.
In addition to making sure that your profile is complete, you should also make sure that you have a variety of recent photos of yourself in your profile. These should be photos that have been taken within the past 6 months.
It's also important to make sure that you're being active on the site as well. Don't craft the perfect profile and then let it sit there. To stay at the top of other member's search results and make sure that you're seen first (and more often than others), make sure that you're signing into your account every day, viewing other profiles, sending messages to other members, and responding to messages that you receive, even if it's just to politely let them know that you don't thing the two of you would be a good match. If you aren't sure what to say when contacting someone else for the first time, check out: What should I say when I contact someone?