It can be frustrating when you're grilling skewers of meat, seafood, or vegetables, and they spin around on the skewers when you turn them. It can happen more so as the items shrink while they cook and leads to uneven grilling. An easy trick is to use the double-skewer method: skewer your foods with two skewers parallel to each other. The food will spin no more! It's also easier to turn the skewers with tongs when you have two sticks to grasp. Make sure meat, seafood, and veggies are cut into large, even pieces so that they don't split when skewered. This works especially well when grilling shrimp because the double skewers splay the shrimp open and keep them from curling up.
There are a number of companies making various styles of double pronged skewers, but slender bamboo ones work just as well. Avoid using fat skewers because it will be too difficult to fit two through bite-sized pieces.
As with any skewers, try to combine items and sizes that cook in the same amount of time. Some vegetables, like cherry tomatoes, cook more quickly than proteins, so consider leaving those on their own separate skewers. Proteins that have been marinated in a very acidic liquid will be partially "cooked" already, particulary fish and shrimp.