I'm just curious, what point would that be? Anyway, what I'm now thinking is both wood and metal could be used as a transition from the grass to the brick ground while wood is used on top of the rest of the brick tiles.

Also, rain is about as cliched as destruct scenery blocks with stars on them. It's just something that takes relatively few tiles in a tileset, and people can decide for themselves whether or not to use it. Though if you want to do rain a little differently from the norm, you can always have it animate in a detailed way.

Edit: I might give Odin's idea a try as well.