My ritual depends a lot on the situation.

Solo short trip: the trip itself is my celebration. It is my get-a-way. I usually just sigh and head home. Depending on the weather I might stop for a cup of coffee for the drive home.

Solo long trip: same as above except I definitely stop for coffee and breakfast (it doesn't matter the time of day, for some reason I always want breakfast).

Non-solo short: We drive around a while looking for a diner. At the diner (I always eat breakfast food if available) we talk about hot showers and reminisce about the funny things that happened on the trip.

Non-solo long: Same as above but usually too tired to talk much at the diner. Comments are mostly one-liners baout how "good the coffee tastes".

The last part of my ritual is when I get home. No matter the trip I download photos from my camera and enter the trip into my log. If I was with others, I send out an email thanking everyone for the company.