Children usually sense when you mean what you say and when you don’t. It’s usually best not to say anything unless you mean it and can say it respectfully, and can then follow through with dignity and respect.
The key to effective limits and boundaries is to say what you mean and mean what you say. This means you need to think before you speak, which generally means you should take time to be calm and consider things rationally.
Don’t set a consequence that you know you won’t be able to follow through on– and don’t follow through when you know you’re being unreasonable or simply acting out of anger and frustration.
Remember, discipline is meant to teach. Set consequences in advance, preferably with your child’s input, then follow through with dignity and mutual respect.