This has been probably mentioned earlier/elsewhere but:

Don't forget to update your email address at least once. (well 2x if you've already got your desired email on file) Click on "My Account" and then click on the button that offers 500 points for updating your email address. MAKE A CHANGE to your email address and anything else in your profile. Submit and you'll instantly have another 500 GoldPoints. Repeat and correct your email address if necessary. You've just earned another 125 miles if you've been doing everything else correctly in this thread!