If you haven't bought sound equipment yet, choose gear that is compact and lightweight. Larger, heavier equipment such as mixing boards and large speakers often comes with hard-sided carrying cases or stow-away panels.
Gather all the sound equipment you'll need for a typical event into one workspace. Include everything you'll need to be fully self-sufficient on the road, including cables, power strip or extension cords; CD players; amplification and control units such as amps and mixer boards; microphone systems (mics, cables, and stands); and sound-producing units such as speakers, floor monitors, and speaker stands.
Measure and record all the physical dimensions of the components of the portable sound system in individual units. Weigh each piece as well.
Divide the equipment into "families" of components. Plan to pack these items together in one or two boxes if possible. Haphazard packing means that unpacking your gear will be time-consuming, and it also frequently leads to leaving items behind by accident.
Build custom "road boxes" to encase the equipment using ¾-inch-thick plywood. Measure the plywood to build a custom box (or boxes) for each "family." Cut the plywood to proper size and assemble them into boxes with wood screws. Take the size of your truck or van's "cabin height" into consideration when sizing the boxes. Reinforce any joints by installing dimensional lumber frames inside the box for extra strength. Lids for your custom boxes should open with hinges, be removable by hinge pins, and lockable with a clasp lock. Install metal corner "caps" on the edges of the boxes.
Line the inside of the boxes with squares of convoluted foam or carpeting. Install 18-inch lengths of dual-sided Velcro inside the lid or sides of the boxes for securing cables. Paint the boxes black and label them with your company stencil and name of the equipment "family," such as "Microphones."
Install four casters along the bottom of the boxes so you can push them along the floor lengthwise. Install four casters along one end of the boxes so you can push them "on end" if necessary. Place grip handles on all four sides of each box.
Pack each of the separate equipment "families" together in one or more boxes if necessary. Don't make a box so heavy that it cannot be lifted by two people. If you are a solo act, plan to pack boxes so they are light enough to be carried by you alone. The comfort limit for most people is about 60 lbs. Items inside the box should not be able to shift position dramatically--pack things tightly.
Remember to pack "expendables" such as spare batteries, black gaffer's tape and replacement lamps for any running lights. Pack any tools you may need to install your sound system, as well as "spare parts" like amplifier fuses. A separate tool box is best for these items.