You also seem to have some rather docile birds. I can never get as close as you do. I´m not sure you would say that if you joined me on a trip. It often takes me a couple of hours of very careful movements and lots of sit-still-and-be-patient time to get them close enough. Some duck species are easy though
The other day I spotted an Eurasian Teal, which is rather rare this far north. It was too far away, but I thought he would come my way, so I sat patiently in a spot, very quiet and still. After a long time I heard a low whisper next to me and I had a giant male swan studying med from 4-5 feet away, with his head and wings held in their aggressive posture and I was sitting on my but, with the tripod and 600mm over my lap. You don´t mess with them! First instinct was to run, second was to sit still, which i did. After a while he lost interest and glided away. Puuhhh! An hour later I could conclude that I would not get an image of the Eurasian Teal ...
You and I seem to have similar tactics and experiences. I spend hours getting close. I've sat, covered in camo, on the muddy shores of various wetlands and ponds and lakes, for hours for birds to get comfortable and close. I think that's just the bird photographer's life...patience. To get the shots of the Ibis, I spent over an hour getting close and waiting for them to do interesting things. I spent about 40 minutes getting some shots of this beautiful Black-crowned Night Heron. It's just how it is...it takes time, and most of the time, you end up with nothing for your efforts.
My equipment is a pop-up hunting blind, a folding camp chair, a thermos of tea, and assorted camera gear. After a while they forget about the hunting blind....
I actually have the Ameristep Chair Blind: http://www.naturescapes.net/store/ameristep-tent-chair-ground-blind.html
It is wonderful when you have the right kind of background trees and foliage to hid it in. When I just set it up out in the open, it's conspicuous enough that the birds still stay away. Also, when it comes to getting the kind of low perspective I like, it just can't get low enough to the ground. I am usually laying flat, with my tripod either entirely flat, or at the next set of notches to flat. When I'm around wetlands, where the ground is always muddy, laying is the best approach...the chair feet just sink and get stuck, the chair ends up uneven, and I'm constantly having to get out and level it or fix it in some way...which kind of negates it's purpose.
The blind has proven more useful for wildlife...deer and prairie dogs. I am also hoping I can find a way to set it up near one of the Kingfisher hangouts so they will stop chattering at me and get down to the business of fishin'.