I have seen many posts that contain something like:
Edit: I would like to do this, but not with that way...
and so on.
Should we include this
Edit: in our posts when we edit them?
Other posts like What's wrong with putting "EDIT: ..." in the body of a post? or When is "EDIT"/"UPDATE" appropriate in a post? seem to suggest that this is not needed.
It looks neater to instead edit your post and edit in the information in a way that makes sense.
This could mean adding a new paragraph at the beginning, middle, or end of your post, or adding in extra sentences in existing paragraphs, but not a separate 'Edit' or 'Update' section.
Usually, no. In most cases, they're just noise, like salutations and signatures. Users can already see that a post has been edited, and the revision history shows what has been added after the initial version of the post.
It might be helpful in some cases to indicate some sort of timeline, if there is some ping-ponging going on between the question and one of the answers. However, I'd prefer if the edit is indicated in a more natural way, e.g.
I've tried the method described in the answer by user12345. However, that didn't work for me because of ...