Love path tiles are usually found on flat or flattish grass, with flowers and water nearby. Usually love tiles will be within 5 - 7 tiles from the shore.
You can create your own love path tile by flattening a low area close to open water and planting flowers on all of the tiles. The are must be created in a minimum 1x2 tile area does not have to be 3x3. Once planted, test each tile to see if it's "special" as the Love Tile does not have to be in the center. If the flowers are ever removed, the special tile may vanish. It must then be recreated, and may show up in a different spot than before.
Sprouts spreading from trees and grazing animals can remove the flowers and therefore destroy the Path of Love special tile.