A weakness is not weakness until you can exploit it. As always, the game remains a balance of attacking and defending. A weakness is simply a flaw in a position that we can exploit. As a result your opponent usually has to create some other weakness.
Spend time examining game play and try to find weaknesses that you can use to your advantage. Completed games on ChessWorld.net are available for players to access and analyse for strengths and weaknesses.
Diagram position is after Black's 12... dxe4 Doubled pawns don't necessarily create a weakness in the position but tripled pawns certainly will. Play the game
Another ChessWorld game I came across where I was impressed with how White exploited the weakness of Black's two undefended rooks.