cause 
is getting another skin and it made me curious as to the process by which you choose who gets a skin. shes a middle teir-ish champ so nothing seems so special about her to warrant all these skins. im just curious.
From what I've read, it seems that riot takes some things into consideration (like how many skins they currently have available and time since last skin release) but that is generally a small factor. They're a bit more on the creative side - some concept artist drew a skin concept that got everyone's attention so they made it, or someone came up with an idea, etc. It could also be that the pool party line had a bunch of ideas thrown around and all the others that they thought of were kinda lame or didn't hit the quality mark, so MF ended up on top.
Eh, I don't know. This is skin #9 for Fortune, putting her only behind Annie. She also received Captain Fortune less than a year ago. I honestly did not expect a Pool Party Fortune or Fiora for that matter (though this is only Fiora's fifth skin).
Now were there better candidates? I think the community would have went head over heels for a Pool Party Swain. Have him turn into a Squid shooting off spouts of water. Would have been hilarious if his bird was a Rubber Ducky. Pool Party Poppy would have been another cute direction, though the runt does have six fine skins already. They could have finally done the Pool Party Katarina that has been shown in the backgrounds considering Katarina hasn't had a skin since Warring Kingdoms (healthy skin pool though). Pool Party Jarvan would have been cool (I have never played the guy but the Teemo/All skits made quite the impression). Pool Party Zyra... Pool Party Heimer... eh... there's actually just a lot of good ideas.
I think the big reason they went with MF and Fiora is because Leona was the only human female in the Pool Party line and the community was a bit peeved with the Pool Party release last year. The community also was displeased with the shared splash, which explains why all three 1350 skins this year got their own.
basically they've said its about who hasn't gotten one recently and who would fit best for the theme, as well as whether theres a skin for that champion already being made or not.
so they probably said we need pool party skins, and made a list of champs that could work, narrowed it down based on who would work really well and who hasn't gotten a skin or isn't getting one soon.
its usually a skin a year right? but some champs still haven't gotten one in a long time. on the other hand, no one wants to see pool party karthus
There are several factors. **1.**If a champion doesn't have many skins then the champ is more likely to get a new skin(likewise a champ with lots of skins gets a bit less priority)
**2.**Likewise if a champion didn't get a new skin for quite some time,then he/she gets more priority(this is why Taric for example got a new skin so early after his rework)
**3.**If a champion is on the VGU list,they are unable/highly unlikely to get a skin(last time they posted it their list consisted of 
and ryze who gets his VGU in the next patch)
Likewise if a champion is part of a roster update,they are also less likely to get a skin(though I think skins without skill effects are still ok)
**4.**Last but not least,if they have a cool idea for a champ or want to make a group of skins where that champ fits perfectly,then they'll might do the skin anyway
Miss fortune likely got the skin because of the 4th point. She was simply perfect for the pool party-theme. You might argue that lucian would have been fitting as well,but he has a rather dark personality,not fitting that much for the pp-theme and mfs skill effects could be used for more stuff than just water effects.
