These are great. You do a good job drawing them, and the poses and expressions you come up with are fun to look at.
By the way, how do you get them to stand up?
Depends on the chibi.
For the first pic, raimu and utsuho have a piece of cardboard taped on the bottom of them (so its like this L) and a piece up the chibi. Then a piece diagonally holding the one up the chibi up, so it looks like a triangle. If a picture helps, Ill gladely take one.
Yuka, though, I was lazy. She has tiny pieces of tape holding her to the pot, and her little hands are mearly being heald by dirt, sleves are taped to the pot.