Print with thick and plenty perimeters and bottom and top layers to make it watertight.
Raising the temperature a bit might help fuse the layers.
If it leaks try using some lacquer or resin on the inside to make it watertight.
Scale it to your needs (only scale up when you have big hands so you can still grip it ;)).
Prints without supports.
Find my Sturdy Planter here: https://www.printables.com/model/279170-sturdy-planter-with-water-level-opening
The author hasn't provided the model origin yet.