1) I used to prepare painting papers and paint directly in front of the motif while sitting in the car, or I'd spread a blanket and paint on the ground.
2) I still use the camera a lot and always have, but there are times when working from the photo just doesn't do it. The data might become too flat, too complex and convoluted, or it just might completely obscure the few essential elements that initially sparked interest in the motif.
3) The top photo is a memory painting and there are countless of those also. Most of the ideas come while I walk. Something seen makes an effect that lingers and the work is painted immediately upon returning home.
4) I'm forgetful and therefore I always have a sheet of typing paper folded up in 4 in my pocket, along with a pen.....I need that in my job to note down things that would otherwise be missed. Plenty of landscape impressions get recorded in this way as well....but they do not become paintings unless the painting session immediately follows....wait a day or even a few hours and the idea is cold. And sometimes on a walk, 4 such 2 minute drawings will be made, but perhaps only 2 become paintings.