You can make good use of platforms for the mines on certain stages such as the new starfox stage (forgot name), shadow moses, the everpopular battlefield, etc....they work well at hindering your opponent's mobility, and you can catch them when they are forced to get grounded trying to avoid a mine with Snake's ownage tilts.
I sometimes plant a full charged one after a KO. Then hope that my opponent doesn't blow it up in his invincibility frames when he comes back next stock (usually doesn't on big stages). Otherwise I usually plant it between my opponent and I after knocking them far, and then hang back and launch nikitas.
Hmm..and you might want to take into account how much damage you have on yourself and relate that to whether you want to charge your mine or not, if you choose to plant one at all (in case you blow yourself up on it). At high damage I don't usually risk having one down, or else just a regular uncharged dsmash that I camp behind.
I mean you can't avoid them detonating it with projectiles/disjointed hits...you'd just have to use it sparingly depending on the character matchup...They're a blessing and a curse really....