But in public,
1. Do not dismiss the criticism. At least show an attempt to at least see where they might be coming from.
2. Do not become combative or antagonistic. Sarcasm counts.
3. Do not use past works to justify the current work.
4. Do not just say that you're doing your best. Everyone is doing their best.
If you do any of these, prepare for a shitstorm, especially if you do any of these on a message board where you're trying to defend your shit.
Actually if you ARE on a message board trying to defend your shit,
5. Get the fuck out.