For landscaping to make ramps it would be handy to have a "slope" option. With that you stand on a ridge or valley and the direction you face, it looks at the low and high ends of the two tile and makes the center the average. If you are not standing on a seam, then it goes by the tile you are on and the closest tile in front or back of you.

When just trying to smooth out an area, "smooth" look at the far edge of each tile adjoining the one you are standing on and tilts the tile to the average direction.