I am uniquely qualified for this as upon being invited to Frozen in Carbonite I really liked the sites goals and as someone whose been mistreated by the SpaceBattles staff on many occasions I decided I wanted to be proactive in helping this site archive Hortons vision. So I contacted Horton, asked to be a moderator, and offered my services.
Horton declined as he did not yet know me, but I did start acting as a recruitment agent working in Spacebattles on his behalf, every couple of days he would link me to a profile he found interesting and I'd invite them to the site. We've had at least some success with this strategy. It's hard to tell as not everyone keeps their username or informs me they're taking me up on the offer.
Me and horton got to talking in these PMs and leaned a big about eachother. After we reached 200 members I again brought up the idea of me obtaining modship and as Celene took a postion as an adviser there was a vacancy.
Beyond that story I'd recommend keeping a good reputation, being mature, and making yourself useful if possible. We don't really need new mods as the site is so small and our reports so few, but at the very least I am always looking for individuals who would make good additions to the staff.