Here's my setup. I went Sediment filter first and then Resin second. I believe that's the proper flow path. Please correct me if I'm "hosing myself" with that method
The only thing I've found is that I can't go full-open on my washer nozzle or I get air since the filters can't catch up to the flow rate of my nozzle. I'll be changing it to an adjustable nozzle with a shower or mist setting and see if that helps. The Flexzilla hoses are a godsend btw. They're crazy expensive for their air hoses, but for the 3 footer and 7 footer I got (for off the spigot), they're totally worth it imo.