What should I troubleshoot if my custom domain isn't resolving correctly after connecting it to Cloudflare?

If your domain isn't resolving after Cloudflare setup, first, verify that your domain registrar's nameservers have correctly updated to Cloudflare's. Use a WHOIS lookup tool. Second, double-check your DNS records in the Cloudflare dashboard, ensuring 'A' or 'CNAME' records point to the correct origin server IPs or hostnames. Third, confirm the proxy status (orange cloud for proxied, grey for DNS-only). Finally, clear your browser's cache and try accessing the domain from different networks or devices.