Electricians on FABO - I want to add a 60Amp sub panel

Sounds like you have been there and dun that to me, only thing I would
add to it would be a # 8 ground to the new panel (body where your ground rod is tide in to you main panel ) to the new sub panel body for your shop, this will be dedicated to your ground rod in the ground.
Locate this new big breaker as close to your main breaker, less heat travel threw the buss bar. and use a bonding grease made for connecting these big wire to the breaker and get them tight .
Remember BE CAREFUL and stay away from the main buss coming in even if (and I am sure it will be) shut off, there's power back there if you don't pull the meter .