There are a lot of different ways to build your setup, clear enough if you've watched any videos with Joseph Zbukvic or Alvaro Castagnet. They're all rather idiosyncratic, meeting the needs of each painter in its own way. I like to tongue-in-cheek suggest it's liking making your own light saber. Each is different and special. I've found a number of posts on the subject over the last few years, from various other artists. I share them here for your reference to suggest alternate perspectives on the subject.
First up is Mike Bailey. Mike writes about his plein air setup in this post on his blog. I've seen him use it and it works well!! It's always good to get a review for tools from an experienced painter. It's a "piece it together" approach. He uses and recommends the Sun Eden tripod mount that I shared as part of a "all in one" approach in pt. 1. It's called the Sun Eden Travel Adapter. He teams it up with a Sunpak 6601 tripod, which allows him to use the Plein Air Pro Traveler's Shelf. In the photo, you can see he's attached an umbrella to the tripod. It's a Best Brella, which I've also used. Wind can make things terrible, even just a little bit, but if you need shade you need shade, particularly when working in natural settings. The post is worth a read- he tells the full story. From those first initial plein air baby steps, to the current (more sophisticated) set up.
Another artist, Joe Cartwright, writes about his set up in two blog posts of his- here and here. It is also very much worth reading. The first part tells the story of his first, failed setup, which used an oil painters box. What I liked about it is that it tells why he didn't like, functionally speaking. Useful info if you are making your own setup! The second post shows us how he made his own. I particularly like how he has the palette up higher and to the side. This is ingeniously done! I've thought many times of doing something similar, as I have the same cheapo palette. The issue is my (rather expensive) tripod. I might need to use my old 20$ tripod to try it out. He also details how he attaches his gatorboard to his tripod, without the use of a T-nut. He glues it! I don't know if this is where I got the idea, or if I thought it up on my own, but as I've done the same thing on my own easel, I obviously think he's very clever! LOL! All in all, a good setup. The goal is clearly to get his easel closer to him and higher up, and to get his shelf and pallet out of the way and where he needs them. He seems quite successful.
It's hard to talk about plein air painting without mentioning James Gurney. Even though his setup is super low key (no tripod at all), he is such a good artist, and so very engaged in watercolor work (amongst other media) that I feel the need to mention him. He has a post all about "Watercolor in the Wild". He talks all about his tools, his paints, his brushes and his palette. It's very detailed, and is an excellent resource. He also has a video for sale, which he and his wife filmed and produced. He actually uses a tripod in the trailer, but I don't think it's listed in the blog post. I've not watched the video, but it has been very well reviewed. It's only 15$ (!!!) and the profits go directly to him. His blog, Gurney's Journey, is also excellent and full of lots of many bits of good info.
Marvin Chew has a blog post about his setup at Parka Blogs. Like James Gurney, he also goes into lots of detail about his brushes, his palette, and his paints. Once again, all very useful info. He uses the Ken Bromley tripod mount I mentioned in the first post, to attach his tripod to his backing. He doesn't seem to use a shelf, but instead holds his palette in his hand and attaches his water to his backing with a bulldog clip. I've seen others do this simple method elsewhere online, but have never done it myself or seen it in real life. His results seem fine though. He also uses something called a Walk Stool. I've never seen this before, but essentially its a high end camping stool with telescoping legs. Seems neat, at the very least. I've used a stool in the past, but the fact that they're either too short and compact when stored, or pleasantly tall enough but too tall when stored made me stop. Who knows? Maybe this is the holy grail of camp stools. Hee!!
Finally, another artist named Marc Holmes, who runs the blog Citizen Sketcher, has two blog posts on the subject- both his older and newer setup. The first posts details out an older setup of his, with the palette to the side, much like Joe Cartright's approach (but fancier). Honestly, I really like this setup- if I could do it and have it by lightweight (and without spending 200-300$) I probably would try it out. I've actually be looking for side-mount photography arms and such to attach to my tripod for just this sort of thing. Marc features a Sirui tripod in his current setup, which I asked him about and have upgraded to. He also has (guess what!) a Plein Air Pro Traveler Shelf. I know, surprise, surprise.... Nobody uses those things. :PHis current setup and my own have a lot in common, outside of the shelf-- although I took the long "neck" out of the tripod. It makes it much smaller when put away, and I also prefer my painting surface to be lower down. Beyond all that, he also talks about all his other equipment- brushes, palette, paints, etc. in the second post. Both posts are very detailed and quite educational. In truth, the art blog Citizen Sketcher as a whole is great. It's one of the few I regularly visit.