Well I'm new to the forum but I'll still put in my 2 cents. I've been detailing on the side since I started driving 15 years ago and have been through a ton of products and methods for all sorts of different scenarios. I've read a lot of articles from detailing a moped to a Bentley and there are many routes to take but I am by far an expert. My grandfather had his pickup for 15 years and I think he might have washed it twice, where I'm lucky if I only detail my daily twice a week haha.
I'm religious about my method on my personal vehicles, what a customer wants is a different story. I have a 1800psi electric power washer that I use for washing. Its hooked permanent in my garage with reel so its an ease to use for me. If my truck is only slightly dirty, I'll rinse and then wash with the 2 bucket method. However if its been a while and has gotten quite dirty, I'll foam cannon, let it soak, rinse and then hand wash with the 2 bucket method. Its a process but for specific reasons and is by far the route everyone wants to go.
Product wise, I use a mix depending on the product needed. I use Chemical Guys, Griots, Meguiars and a couple odd ball products. Also been messing with Optimum products lately. Theres not too much out there that can really hurt your vehicle if used properly, just make sure to follow instructions but biggest thing that some products lack to mention is you don't want to do anything in the sun or if the paint is hot if you can avoid it.
Hope it wasn't too long just want to give a general run down.