How about just not having one? i am often interested to try things but I am not giving out my CC until I've tried it out, FOMO be damned. I don't want the burden of cancellation if I decide it's not for me, I've been burned before by forgetting and paying for a service I didn't want.
We think this is the most sustainable option because there is a cost to providing a quality service. We take a small loss on every user who cancels their free trial - more than a typical SaaS because AI models are expensive to serve.
Personally I only need about 30 minutes with a code autocompletion LLM to see if it will do what I want without pissing me off (and maybe even making me smile!)
How about taking the CC but not subscribing the user. As in the CC is used only to verify the user but I have to subscribe once I consume my free credits (even though the CC is on file).