First off, I apologize for this being a day late, there were some technical difficulties on my end when trying to get this up, so here we go :).
This is a great location for almost any aggressive deck. You can use this to force your opponent to attack one of your stronger creatures, or use it to protect your back line creatures.
Once it can trigger its mirage ability and you can place it on the battleboard, you need to determine if you want to use it offensively, or defensively. If you want to use the location aggressively, you should place it on a strong creature that you control that is near your opponent's back line. That way, your opponent will be forced to attack your strong creature, even if it is a weak mugic caster. If you want to play the defensive route, you should place the location on another strong creature you control that is in front of your mugic casters. No if your opponent wanted to move in on your mugic casters, they will need to move in on your stronger creature instead of moving into your mugic caster's space.
This isn't the only mirage location that is of value in Silent Sands! Try to see if you can find a good location that can fit into your strategy.