I thought his special ops S.H.I.E.L.D look was dope. Mackie himself though, did say that he would have liked to have the red and white comic book look so he could dress up as himself for Halloween. Here is his comic book look.
It looks like a typical costume, but is actually armor. In [The Avengers: Age Of Ultron](movie:293035), Tony Stark makes Cap a new suit.
If I'm not mistaken, Falcon was seen on the set. I think that while T'Challa fixes Cap's shield in Wakanda, Iron Man will make Falcon a suit to replace his old one.
Tony made a more advanced suit for Sam. It was actually an Iron Man suit without the helmet and a little less bulk. Watch the last few episodes of Avengers Assemble to see that suit.
Long story short, in Avengers 2, have Iron Man make a cool suit for Falcon. It would be red and white of course. A helmet for a mask like Cap's, a protective but thin suit of armor, and it would be cool to have space capability. If he had a concealable mask like Star-Lord's so that space can be pulled off. That will be the suit that Falcon uses in [Captain America 3](movie:994409): The Fallen Son. (I don't know if that's the confirmed title, but everyone seems to call it that). I think it can be pulled off. Come on, why else would he have been seen on set? He's not a main character for the sequel.