I purchased a 6x12 tandem axle enclosed trailer. It's well-used, but in good shape. I keep all of my tree gear in the trailer. The trailer houses my hedge trimming gear, weed trimmer, blower, rakes, shovels, climbing gear, saws, gas cans, bar oil, etc.
Along one side of the trailer I mounted a pickup toolbox that I use for storing my ropes, rigging gear, climbing gear, throw lines, weights, etc. All of my climbing and rigging gear is stored in bags that I can quickly pull out of that toolbox. The aluminum toolbox protects the ropes and saddle from getting nicked up by saw chain or the hedge trimmers, as well protection from gas and oil.
The trailer idea isn't for everyone, but it sure makes my life easier, due to the fact that some of my tree jobs are more than 40 miles from home. It's a real pain to find out that I've forgotten something when I'm that far from home.
Joel