I want to keep my RDS instance when I destroyed my pulumi changes. I imported my RDS (no problem with that). But whenever I finished my tutorial/experiment, I'd like to destroy everything except for the RDS. Right now, I'm using

pulumi state delete urn:pulumi:production::blog::aws:rds/instance:Instance::blog

After that, I'll uncomment the code rds code and run

pulumi destroy

Is that the way to do this or there's a better way to achieve this?

I don't think so. If you use

protect: true

then it prevents the destory, iirc. You need to remove it from the state to leave it after a destroy.