Actually the #1 rule can change depending on the value of your rocket.
#1A: Ensure it's attached. I've seen at least one fall free of the rocket and have heard of others losing theirs. Becomes a very pricey one-time chute release!
And doubt that you attached the JLCR then go back to check again...![]()
Bring your phone, and photograph it attached and turned on before leaving the pad. If you have any doubts, look at the picture you just took.
I started doing this and photographing the internal wiring of my av-bays because I kept having those niggling doubts too while it was out on the pad.