I play mostly as an engineer and few things feel better than getting land mine kills. Straight up.
I put all land mines down in a triangular shape a few feet apart. If a tank hits one they’ll all go off. Dead tank. Unfortunately you only have three mines (without upgrades) so try to take out the best vehicle you can. 
Note you’ll often see mines in straight lines. Effective for stopping jeeps, but if a tank hits one or two it’s not enough to kill it unless it’s already been damaged. So I go for the layout above.
Before you spawn in look and see if you can spot enemy heavy vehicles on the map. These are the targets you should be going after. Where will they most likely be going next? The closest point controlled by the enemy.
Find the pathways where their traffic will most likely be. Find the best spot you can and get your mines down.
Remember that land mines can be seen. So I usually look for existing debris, explosion foxholes, railroad tracks, or other bumps in the road. Put your land mines here. You’ll want to put them on the opposite side of the traffic flow. Vehicle operators usually don’t see them and will ride right over top of them.
If the existing debris is something that must be driven around that makes a nice choke point for you to place your mines. You know where they’ll be before they do. Use it.
You can only have 3 land mines (again – without upgrades) on the field at once. These exist even after you die. However if you die and start placing new land mines down your old mines will disappear. If you have them in a good spot and die, don’t place new ones. Wait for the trap to pay catch someone and then place the new mines down.
One of my favorite things to do is to lure tanks to the land mine trap I’ve set. If you place your mines down and they aren’t taking the bait shoot your rocket at them then run and hide on the opposite side of your mines. Launch a pot shot or two and they’ll come determined. Sometimes I just shoot them with my rifle and run. That usually works too.
Last thing I can say is don’t forget to laugh. It’s a great feeling running 1000 yards away on the map and suddenly get 450+ points flash on the screen from a set of land mines you dropped a minute ago.
Happy playing! Any additional tips leave me some comments. Always interested in hearing
Marklar Gaming 