Use your vehicle's roof racks for ratchet strapping hardware from your favorite big box retailer. As opposed to personal items that may require the use of a box for long-distance travel, joining cargo being used for a project is bit easier to deal with because it's going from point A to point B. Run the hook and the ratchet over the equipment, letting the mechanism on top of the items. Then run the other hook over the items as well and run it underneath the rack to meet the closed-end of the other hook, therefore creating a redundant connection.
Getting the best out of a set of roof racks is about knowing a few best practices - consider how much weight the roof can deal with; stack items evenly in order to distribute the weight; and put the lighter items on top of the heavier ones.
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