I like AndresQuijas's flower pot so much but there are no drain holes on the bottom of them, so there will be a risk that the root will rot.
However, simply add holes on the bottom of this and put it on a water tray will ruin this nice design, so the “water tray" must be hidden.
And I modified this one based on the original design with holes and ramped bottom for each small section. Therefore there will be no more water stay at the bottom and make the root go bad.
The slab is removable, so when you need you can remove it and clean the gutter in the middle.
There is also an idea about making this design into a self-watering model. I might will do it soon.