During competitions I use a box from IKEA for carrying stuff to the firing point. It is particularly handy when changing area is far from the firing point, then I can go in two goes: one go to carry the rifle and stand, and another go to carry everything else in the box. When not in use, I pack the box and use it as a frame for my jacked packed in the shooting bag.
I had a chance to listen to a recorded lecture by Aleksandr Kudelin from Scatt. One of the main messages was that humans cannot focus attention to more than 1-2 tasks at a time. During a shot release one needs to keep under control at least three elements: hold, aiming and trigger release. Hold is the most important, and the most trainable element. One can train endurance of hold, stability, and coordination. Endurance is trained by holding a rifle or a dummy. Stability can be trained by a static aiming, or slow motion following a drawing, for example, a digit 8, spiral, triangle, or written letters. Coordination can be trained by eliminating the sight picture, for instance, firing to a white paper, or eyes closed.
Many shooters do something else for a living. I looked at the data about athletes participating in air rifle disciplines at ISSF World Cups in 2014 and 2015 (up to Gabala 2015, which is not included). In total 566 different athletes participated, out of which 348 indicated their professions in the athlete profiles. Out of those, 42% are students, 15% military/army and 14% athletes. All these are more or less full time sportsmen, so it means that bout 70% are full time sportsmen, and about 30% are kind of hobby shooters.
Here is a wordle of indicated professions.