People seem to use the same things that get used for hunting; blinds, camo clothes, etc. And the same as hunting, I think the skill to develop is knowing about the animal. Where do they move thru regularly? What times of day are they moving? Food, water or shelter? I see birders all the time in more camo to take pics than I would wear to hunt, including covered lenses and tripods. I do think if I took time to set up a blind near some of my feeders this winter, I would get some of the skittish birds more easily. Certainly something I may likely do. And after noticing that I always seemed to be wearing a bright coat when the hawk/eagle was perfectly posed, I did throw an old black shell in the car to put on when needed. The long lenses are good obviously but patience and more often, right time, right place have the most results.
Have a look at Cabela's website, they have the whole camo/blinds/scents etc. thing in many price ranges. I've certainly eyed some portable quick pop up blinds once or twice. But having spent many hours in duck blinds, cold, many times wet and in the company of anxious dogs, I know it takes serious patience to do what you see those videographers do. That may be their most valuable skill.