Transparancy is important with compels, self-compels specifically. If a player is intentionally trying to get a FP, they should probably announce it up front toake sure the GM feels it's compel worthy.
Stepping in gum while walking down the street isn't a "meaningful complication". Falling down an open manhole while walking down the street is. Or if you need something a little less Looney Toons, tripping over a rock and breaking you wrist while walking down the street.
If a player does something worthy of a self-compel without realizing it, it's usually a good idea to just give them a FP, even if no one catches it right away. Though it's not typically a good idea to throw out fate points to players when they believe they have a good plan, and it just so happens to go south. Basically what I mean is bad dice rolls or failure to gather vital pieces of information on the players part doesn't constitute a FP IMO.