I place most next to or close to the water ,they don't have to land in the water but the boxs will get more use if it is very close or on the water . I put my boxs up and chech the old in the winter so I can walk over the ice to all of them 50 or so this year.
put a few inchs of saw dust or wood shavings in the bottem
if you use a metal stake ,put the stake through a 3' piece of plastic pipe to serve as a predetor gaurd
I like to place the boxs in the edge of creaks , ponds ect in afternoon shade if posible to keep the box temp down ,don't know it helps but can't hurt