Skills and skill-like mechanisms primarily do not describe what a character can do, rather they describe what a player, especially a Referee, cannot do.
The Thief of D&D is an excellent example of this axiom. I have never been fond of thieves. Apart from my discomfort at their explicit association with illegal activities, I have played in too many campaigns where players with thief characters felt that they needed to break the law. Too many times has party cohesion been damaged by players who try to use their thief skills on other party members. Too many times have I been forced to kill entire parties because a thief dragged everyone into a fight with the city guard over a failed pick pocket attempt. But I digress.
The thief class is defined by their ability to use skills — Open Locks, Remove Traps, Climb Walls, Pick Pockets Hear Noise, Move Silently and Hide in Shadows. As a result these skills tended to become explicitly Thief skills — everyone else at the table was no longer able to use those skills. In other words, the thief class defines what every other player cannot do. It doesn't matter how well anyone describes how their magic user is going to disarm a trap, with the thief and his skills in the game, magic users aren't allowed to disarm the trap — they don't have the skill, so they can't roll for it. Ultimately, this kills creativity. Why bother to describe a creative way for anybody to disarm a trap when the rules will determine that you fail anyway? It doesn't matter if I have a degree in mechanical engineering and can describe exactly the way a trap might function, and exactly how to destroy or stop that mechanism. If my character doesn't have the skill, I am not allowed to disarm that trap. Mechanics start to define the character instead of the player.
There is a way to beat the system, however. Let me begin by giving an example of a great rule:
Love your God with all your heart, with all your soul, with all your mind and all your strength . . . and love your neighbor as yourself. — Mark 12:30-31
When Christ gives us these two commandments, He sets up boundaries beyond which we should not pass; however, within those boundaries we are allowed complete freedom. In other words, good rules don't limit freedom.
Skills can be used in a way that they don't limit what players, especially referees, can do. The key is to understand that you have the power to say no to the skill check. If a player successfully describes how to accomplish something they should be rewarded with success no matter what skills their character has. Don't force them to roll the die — don't kill the creativity.
To give a concrete example, let us look at the D&D thief again. One way to describe this mindset is to understand the thief skills as abilities, not skills. In other words, they are things every one can do, the thief is just able to do them above and beyond the normal adventurer. Thus, every other class can hide, move silently, etc. The thief is just better at it — if he fails to successfully describe how to accomplish a task — using the same criteria as everyone else — he gets a "save," as it were, by rolling the die to use his Thief skills. As abilities, as opposed to skills, they no longer determine what players cannot do.
Don't kill the creativity at your table. Just say no to the skill check.