A question I get a lot is "Can anyone be a Wonderbolt? How do I sign up?" or some variation thereof. It makes sense; I'm pretty much the #TwitterPonies' go-to guy for all things Wonderbolts. So here's what I have to say on the topic.
Keep in mind that there's no "official" anything on #TwitterPonies. If you want to be a Wonderbolt, it's not like I could stop you. (And for that matter I wouldn't particularly want to-- despite what a few misguided souls may think, most of us have better things to do with our lives than try to dominate a fictional world made up of cartoon ponies.) I'm assuming that if you're reading this, your real question is "How can I be a Wonderbolt that Soarin, Spitfire, Rainbow, et al. will play with?" So that's the question I'll attempt to answer.
Three Ways to Join
Wonderbolt From Scratch
This is the easiest way to create a Wonderbolt character: just set them up as a Wonderbolt from the get-go. If you're going to go this route, it's probably best if you assume your character has been with the WB for a few years. The way we generally play it is that the WB don't get new recruits very often, mainly to explain why Rainbow Dash isn't in yet. (More about that below.)
Then, just start posing! @-mention Soarin a few times and I'll take a look at your character. There are some tips later on for how to play an awesome Wonderbolt.
Joining the Team
Having an established character join the team as a new Wonderbolt makes things a lot more awkward, and we try to avoid it. We did a big "Wonderbolt tryouts" story a while back, and it was very cool, but it was also a huge production and a lot of work. Speaking only for myself, I don't really want to go through again! :D The biggest problem involved is, as I hinted at already, "If the Wonderbolts are taking new members, why isn't Rainbow Dash in?" We solved that last time by having a freak blizzard call Rainbow away from the competition before it was over, causing her to lose by default. But we can't keep doing that over and over again.
That said, there are ways you might "transfer in" to the Wonderbolts. If your pegasus has guardpony experience in their past, or has been a member of some other related organization, you might get "traded" to the WB in exchange for some background NPC. Or it could be that you've been "on reserve" until now and are coming in full time to replace a background WB who is retiring.
Basically, any way you can come up with to "have been a WB all along" or otherwise get around the fact that the WB don't take new members at the drop of a hat will help. Note that "They HAD to take me because I'm just THAT awesome!" is not a good reason. :P
Consider an Academy Cadet
The existence of the WB Academy opens up all sorts of cool possibilities. Being a cadet would allow you to get into all sorts of cool and interesting WB scenes without having to explain why you're in but Rainbow's not. It would also allow you to take part in Cadet Training scenes, which we intend to do more of going forward. You wouldn't be an official "full-blown Wonderbolt," but you would still be part of the gang.
How to Be An Awesome Wonderbolt
Okay, this part's very subjective, but since the goal is to impress us veteran players so we'll deal you in, here are some tips.
First: The Wonderbolts are Awesome, But They're Also Kinda Ridiculous
This is a tricky line to walk! The Wonderbolts are the best flyers in Equestria, doing death-defying stunts and throwing themselves headlong into danger in order to protect the safety and freedom of all Princess Celestia's subjects. But the first time they actually made a rescue attempt in the show, they got knocked cold by Rarity(!). More recently, Spike bodyslammed the bunch of them into the side of a mountain. Granted, he was huge and monstrous at the time, but still!
A good way to look at the WB are like pro wrestlers: everything is turned up to 11 and constantly hovering somewhere between "really cool" and "really silly."
Second: Have a Specialty-- But Don't Steal Somepony Else's
Having a gimmick for your character is great. Obvious gimmicks for WBs are speed, agility, or some kind of flashy special ability. Whatever it is, try to make it something unique that doesn't steal the thunder from someone else.
Soarin's bit is strength: he's the Big McIntosh of the Wonderbolts. He can also generate a cascade of lightning if he's going fast enough. Spitfire is the Most Awesome of the current roster of Wonderbolts. She just is. She's also the leader, and creates a cascade of fire. Surprise is the "Pinkie Pie" of the WB, creating baffled looks right and left, and so on.
Remember that these specialties are relative to the other Wonderbolts. The WB have minimum requirements for speed, agility, strength, etc., that they've all met. We're all among the top ranks for those, or we wouldn't be Wonderbolts in the first place. Therefore, your specialty and/or gimmick is probably the thing that got you on the team, and it's worth putting some thought into what that might be.
Third: Please Avoid Drama
I don't know why, but in the past the Wonderbolts have sometimes felt more like a soap opera than a sports team. Angsty or non-stop shipping, shipping-turned-sour, jealousy, resentment, yadda-yadda-yadda... all of these are literally anti-fun. If your RP is full of this junk and makes Soarin feel like he's the only adult in the room, I will quickly stop interacting with you. The Wonderbolts should be over-the-top adventure and showmanship.
Fourth: Get to Know the Team
Teamwork is at the heart of the Wonderbolts, which is one of the reasons why the point above is so important. (Drama kills teamwork.) We don't do shows in the feed as often as we used to, because they're complex and require a lot of coordination between players. But if we had a solid team of good RPers who interacted well, I'd love to start them up again. The current roster as far as I am aware is:
"The Wonderbolts" (@mlp_Wonderbolts)-- A utility account that covers background WB, stage business, announcements, etc.
Spitfire (@mlp_CptSpitfire)-- Captain of the team and badflank motherhugger. Creates a cascade of fire. Player is often busy but gets on when they can.
Soarin (@mlp_Soarin)-- That's me! The ColtSpice Guy. Big, warm-hearted, fun-loving, not always the sharpest spoon in the drawer. "Most Powerful Flyer in Equestria" and noted pie fiend. Creates a cascade of lightning.
Coach (NPC)-- An NPC I created to torment Soarin. A former WB himself and a grizzled old drill-sergeant of a pony who is prone to crazy ideas that we have to try to find some way to implement.
Kiryn (@mlp_Kiryn)-- Chief engineer for the WB, rather than a performer. She keeps all our gear in good shape!
Glyde (@mlp_Glyde)-- Part-time WB and full-time dad. Also works with the guardponies on the side.
Lightning Strike (@mlp_LightStrike)-- Assistant coach, also acts as a liason to the Crystalbolts.
Surprise (@mlp_Surprise)-- The Wonderbolts' answer to Pinkie Pie. Kind of an oddball with somewhat spotty attendance, but a good-natured pony.
Fleetfoot (@mlp_Fleetfoot)-- A cool and laid-back Wonderbolt whose specialty is speed. Player seems to be mostly inactive at the moment but pops up from time to time.
Several others have come and gone, these are the ones that I'm aware of as still posting. If there are others I should be aware of, please mention them in the comments!
Finally: Be Consistent
A particular pet peeve of mine is people who start scenes and then wander off in the middle of them, or who are totally cool one day and then a big jerk for no apparent reason the next. I certainly realize that this is an online RP and stuff happens, and I hardly demand Shakespeare. But purely from the standpoint of "How do I get the core WB players to want to play with me?" this is kind of a biggie. :) Players who post regularly and RP well are much more likely to grab my attention than someone who posts once or twice and evaporates or otherwise flakes.
So How Do I Start?
Well, that's easy. Create your Wonderbolt and start playing. :) Toss a few @-mentions Soarin's way and I'll check you out when I can. Assuming you follow the tips above, it'll be just a matter of time before I start sending mentions back.
Hope to see you in the feed!