My developer account has expired and I'm not ready to renew it, but I'd like to build/sign/test an app on my own devices for the next couple months before renewing. Is this possible and how do I do it? The developer site seems to insist I renew before allowing me to create signing certificates.
You must be enrolled & paid up.
I'd like to build/sign/test an app on my own devices
You can build and test your apps on your devices if you have an Apple ID used as Developer account, paid or not.
The restriction is a bit stronger than paid membership, but it may not be a big issue when you just want to use your own device.