Make a list of all the characters in your icons. (Although you may have more than one icon of a single character, they only go on the list once.) Alphabetize it. Take the first two people on the list; that's your first pairing. Second two people; second pairing. etc.
Michael (Little Britain)/Rayne_y_Daze whee!
Riley/Sebastian (Little Britain)
Snyder/Spike Um, yeah. Moving right along...
Trick/Two Unidentified Guys on a Beach