Treat others as you would have them treat you. Such a simple sentence, but so hard in practice. Most people are not, in fact, negotiators. Trying to perfect that skill "on the job," during your own job search, is a risky path to take.
Be prepared. Know why you are leaving and what you want in a new role and stick to it! If you don't like your manager, your current company giving you more money doesn't fix that. Nor does only looking for a big pay raise in your next job. What lessons have you learned to better prepare for the questions you should be asking.
Finally, you only have one reputation. Don't ruin it by ghosting someone. Treat them with the respect that you would want to be treated with.
More job seekers are juggling multiple offers at once, creating sticky situations for all involved. How well candidates manage them can shape their long-term career satisfaction, and their professional reputations.