I think an important skill is knowing how not to be a person who causes trouble for others -- riding predictably, calling out obstacles and speed changes (slowing, stopping), recognizing that others may not be comfortable if you pass them with only a few inches of clearance, things like that. And letting people know if they should not follow you closely, e.g., if you plan to stop frequently (such as to take photos) or encouraging them to pass you if you're not comfortable in a large group.
As for skills, emergency stopping would be good. I've had to grab my brakes a couple of times to avoid crashing into someone who stopped unexpectedly in front of me and ended up fish-tailing both times.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles