I've used cargo bars that you can position across the bed to hold stuff in place. I've also used a "spider net" to keep things from moving. Both of these work well when you also have a rubber bed mat - which I've used in my trucks since around '98.
The bed mat has been better for me than a bed liner and its easy to pull out a clean it and the bed. Biggest drawback is they oxidize and can leave black marks on your stuff (and your hands) after a few years of baking in the Texas heat and sun.