Just ask how was your ride, and be okay with listening to someone vent about close calls and terrible drivers. Never try to criticize, take sides, or add any kind of potentially negative feedback into the conversation. Personally, venting helps, but most if my family and friends can't handle hearing about it. So I'm constantly bottling up that tension and frustration. That stress can be as bad as the physical fatigue at times.

As far as gifts, a real roadie's bike is like someone with a really unique custom car. You should probably avoid gifting them anything for it unless they specifically tell you what they want. I never want some dumb trinket on my bike. I only carry what is absolutely necessary. Anything else is a burden and working against me.