I usually ignore mild critics or those who provide constructive criticism (or I might thank the latter.) However, for the most malicious critics, there’s a fairly easy way to wear them out: keep asking them why they what they think. A lot of times, they didn’t mean to seem so harsh and will objectively explain their position. But those who are maliciously trolling will double down and insult you. Just play along: if they call you names or stupid, then ask why they think you’re stupid for example. At this point, your goal isn’t to win the argument, it’s to wear the troll out by getting them to spend as much effort as possible while you spend as little effort as possible to keep the conversation going.