If I have the nuts, I'm check-calling to disguise my hand strength. Let them make the mistake. However, if the board is paired, I'm check-raising. My opponent might think I've hit a full house. If he re-raises, your flush might be dead. Fold it. If I'm playing suited connectors, I'll re-raise them PF out of position (SB/BB) to signify strength, making your decisions on later streets easier. Aggression is key. Don't get out drawn through passive play with low suited connectors, BUT be prepared to fold them.