1. Make changes naturally: when making changes, pay attention to keeping the whole work harmonious and natural. Don't make the change too obvious or abrupt, so as not to affect the overall effect.
2. Minor changes: Try to reduce the scope of changes and don't change the whole work. You can gently erase the original handwriting, then rewrite it in the correct order, or slightly modify it with a pen.
3. Don't destroy the overall aesthetic feeling of the work: when making changes, you should follow the basic norms of calligraphy and don't destroy the overall aesthetic feeling of the work. If the change will affect the layout, momentum, rhythm and so on. The whole work, it is best not to change.
4. Signature can explain: If you feel it necessary to explain at the signature, you can add a note or explanation at the signature to explain this small mistake. But the notes or explanations should be concise, which will not affect the appreciation of the whole work.
In a word, calligraphy is an art form, and any change needs careful consideration. If changes are needed, we must follow the basic norms of calligraphy and maintain the overall aesthetic feeling of the works.