Find a good spot, with some cover fairly close to a deer trail if you can, and put out the cheapest salt you can find. All the mineral deer mixes have salt added so deer will eat the mix. If all you care about is attracting deer, a bag of plain salt is the cheapest option.
For a good mineral mix, the Evolved Habitats "Rack Up" has the best mix of minerals with just enough salt thrown in to get deer to eat it. OF course you'll never know how much the deer may have benefited from the stuff but if you don't mind spending a few $'s to get any little improvement possible you might consider it. I've used it a lot in the past but the last few years have bought a salt mineral mix made up by the local CO-OP. Deer use both about the same. Again there is no way to ever measure any difference in improved health for the deer.