opinion: installing fenders

[69Tom]

Quick question for you guys. When installing fenders, and the fenders in question are aftermarket, do you install with the fender wells attached, install the fender well then the fender, or just install the fender and install the fender well last?

I'm half considering painting the fenders while on the truck as I need to start using it for various tasks, so I'd paint the insides of the fenders and probably prep the inside areas that receive body color before installing.

I've seen suggestions to install the well first, then others say to install it last. So just seeing based on experience what technique people like to use.

Thanks.