Setting up a custom domain with Tolt is pretty straightforward, you just need to create a CNAME record for your desired domain(i.e. affiliates.tolt.io) and point it to domains.tolt.io.
But, if you're using Cloudflare as your DNS provider then you need to make sure the CNAME record is not PROXIED.
To do that, just turn off the "Proxy status" switch, as seen below:
The reason for this is that sometimes some of your Cloudflare settings like Rocket Loader, might interfere with Tolt, meaning your affiliate portal might not load correctly.
Although Tolt uses Cloudflare under the hood for custom domains, so nothing to worry about since the traffic will be proxied by our Cloudflare account.