Given that each map has around thirty (known) spawn locations, camping one spot would likely be a tedious waste of time. Unless someone finds (or destroys) the box, it'll stay where it is, so you'll be camping a spot which has zero chance of spawning a new box. (But each box does spawn in a different place each time.)
Instead, learn the locations of a decent number (but not all) of the spawn locations on a particular map. (There are many excellent video guides that people have spent time creating and putting online, which make it a lot easier to get a feel for the box locations from the in-game point of view.) Choose a bunch of locations which are close together. Then go on a tour of all of those locations, one after the other, round and round, until you get lucky. If you've tried a few times and not found the dog tag for that map, then learn a few additional spawn locations and then add those to your patrol route.
Do not waste your time with a "dog tag hunt" server, because every person on those servers is also looking for the same thing as you, which gives you almost no chance of being the one to find it. And don't join an empty server, because at least four people must be playing, otherwise the box will not spawn.
I'd say the best bet is to simply join a match (always Conquest Large) which has been running for at least ten minutes, and then simply fight your way from location to location, using small, fast vehicles whenever possible, and trying to avoid running straight into massed enemy positions. Because you'll be focused on the nooks and crannies dotted across the map, and not on the objectives, your score will plummet (though not as bad as if you'd gone to those zero combat "dog tag hunt" servers or stayed still on one spot) and you'll be almost no use to your team. But, with patience, you will eventually run into one of those tiny little boxes.
For some reason I kept bumping into the things on Giants Of Karelia, and didn't have too hard a time on Whiteout, while Hangar 18 took some patience, and Hammerhead took me longer than the other three put together. But the box is spawned randomly (at any of the spots shown on the maps to which you linked) so it's ultimately blind luck how long it takes. Just don't stay still. And don't forget that you must knife the box to open it up; never shoot it.