Active player would also be advised. I don't see you a lot in teamspeak and getting to know everybody gives you a lot of opportunities. I wouldn't be staff if it wasn't for teamspeak. Get on it and don't be afraid to talk and say something.
Ranger in my eyes, is more like that friendly dude(tte) that hangs around a lot and helps the newbies find the ropes. Sort of like tito from rocket power on nickelodeon. He's friendly, can give help and knows where everything is whether it is a location on our map or a guide on the forums. He can also guide people around and that's where teamspeak comes in, most guides don't want to typ that all out. Having teamspeak gives you the opportunity to be a bit more noticed as voice chat is a bit more noticeable than chat and to talk through the lengthy explanations. Like tito, you also know how to surf a bit and doesn't need the rank ranger to help a person. Most rangers get promoted because they already are a sort of ranger or have all the characteristics of one.
Knowing staff and staff knowing you also helps a lot, since we need to be able to put trust in you as you gain a bit or responsibility. To be honest, now I don't really know you or have met you as I know the other rangers or the majority of the active commoners. (again teamspeak helps, just getting to know each other).
For example:
Fornad has been online longer than most, he knows his lore, he knows the server, he can do some graphic design, he is somebody who takes initiative to start fun things like tours or videos and everyone knows he's a nice dude.
SugarKoala is a very nice person and will help you untill her hair falls out. She is very active and knows most of the time what's going on on mcme, so whenever you want to know something you can ask her and she'll respond in her ever friendly voice.
Darthragnar is a rock, he's always there and dependable and he'll drop whatever he's doing to help you out or give a tour. He's not the most talkative but every time I log in I can see darth helping another droog. He doesn't make drama and has been around for quite some time.
Indo is the same, he'll work to get his lore in order and will give a tour even if all odds are against it. He's fun to hang around with and doesn't cause any problems or confusions. And again, he's active whenever he can.
Kyz, he's always working harder and harder to be a better ranger. He will do whatever his friends ask as a favour and will help even the most annoying droog on the server. He's not a quitter, cause it took quite a while for him to get his rank but he still got it. Even if he's not that fluent in this or that task he'll try it anyway and give it his best.
If jake sees someone being sad or helpless, he'll take of his super-awesome-canadian-tough-guy's-hockey-mask and will help whatever you need.
Seeing these examples might give you a better idea of what a ranger has under his belt as characteristics.