What steps should I take if I am migrating from another web hosting provider to Netlify using Cloudflare?

Before migrating, back up your existing website content and database. In Netlify, add your domain and configure the site settings. In Cloudflare, create the A records pointing to Netlify’s load balancers (or Netlify’s IP addresses), disable the orange cloud (proxy) initially for the A records, and configure the CNAME record pointing to your Netlify site URL. Verify the DNS propagation using a DNS checker. Publish your site on Netlify. Finally, switch your DNS to the Netlify settings. Thoroughly test your site after propagation. Once the domain starts working, you can optionally enable the Cloudflare proxy for the root domain A records, which should now be working correctly with Netlify's setup (including your auto-generated SSL).