An attack on a castled position is usually more dangerous along the h file than along the g file, the h file being further away from defending pieces and not as easy to cover. Ján Markoš, The Secret Ingredient To Winning At Chess
The side with the IQP has the following four plans available: A) kingside attack; B) opening the game by advancing the isolated pawn; C) advancing the isolated pawn in order to fix an enemy pawn on an adjacent file; D) developing activity on the queenside. Boris Zlotnik, Zlotnik's Middlegame Manual
It took me 20 years to realise that the best way to evaluate a position quickly is to look closely at the bishops. Roddy McKay, quoted in Chess For Zebras
Minor piece or three pawns? The closer a position is to an ending, the more likely it is that the pawns are better than the piece. Edmar Mednis, Practical Opening Tips
As an extremely rough guide I tend to think of IQP positions with four sets of minor pieces as favourable for White, ones with three sets of minor pieces as about level, and when it gets down to just two sets then things are starting to turn Black's way. This rule assumes that White has the IQP and that the major pieces are still on the board. Joe Gallagher, Starting Out: The Caro-Kann