Realize that others are at other points in their lives. That just because the code does not look the exact way you would write it does not mean it is not bad/wrong. There is always one more refactor to do. There is always more bug. Worry about what you can do. Help others when they need it (not when you want to, this is tricky to not become the knowitall guy).

Delegating is knowing that you need to let go and ingest the fact that they are there to help. Mistakes happen and will happen. But that is part of learning for you and them. If they are not learning that is a different issue. Do not worry about it. You will learn what you can put them on better. But once they learn something they can turn around and help you learn. They can take care of it and you do not have to worry. Delegation is trust. Learning to trust is learning to 'let go' and being open to being 'hurt'. But also being willing to forgive and forget.