Grenadiers can trigger Shock Mines with their grenades, so Shock Mines are very unlikely to come into play if you use Grenadiers throughout the attack.
When using Warriors, Shock Mines located on the preferred path can easily be taken out of the equation with GBE. However if singled out mines appear within a tile of any building on the path, it is best to Flare to that building and drop a Smoke on it so the Warriors can group up and recover from the shock before the next Flare is deployed.
Place them away from defenses that are likely to be attacked by Artillery and Barrage before troops are deployed, in order to prevent attackers from triggering them prematurely.
Place Shock Mines away from each other to prevent several from getting destroyed at the same time.
Never place a Shock Mine next to or within one tile of the Headquarters, as when Warriors reach the building under a Smoke Screen the shock duration will not outlast the Warrior's cover, and they will all hit in unison like normal.
There are no visual changes as the Shock Mine is upgraded.
As the Shock Mine is upgraded, its damage increases by approximately 10% and the shock duration increases by half a second per level.