Lie for them.

Make excuses for their behavior.
Correct (or pay for) their mistakes for them.

Model a lack of responsibility, commitment and follow-through yourself.

Refuse to believe that they are capable of doing what they've been accused of doing.

Fight their battles for them.

Tolerate and excuse abusive or unacceptable behavior from them or others in order to avoid additional conflict.

Be sloppy about holding them accountable for their behavior, especially if you're tired, frustrated or starting to wonder if it's worth the bother.

Routinely let them get away with things if they have a good enough excuse.

Do their chores and take on their responsibilities. Tell yourself it's easier to do it yourself.

Let them have privileges anyway, even if they haven't followed through on their commitments or what was required first. Use rationalizations like, "Just this once," or "OK, but this is the last time." Add, "I really mean it this time," even though you don't.