Many species of trees can be grown as bonsai. It is even possible to grow redwoods as bonsais. Stunting tree growth keeps them to a miniature size.
Garden container size
The easiest way to grow miniature trees is to grow them in a small gardening container. The roots of the plant are restricted for growth, and this signals the tree above the surface to limit its growth as well. Plants' roots can sense its surroundings, including the size of the pot it is in, and increasing the pot size allows plant size to increase proportionally.
If this method is used, precautions have to be taken. Drainage, nutrient supply, and preventing drying out must be taken care of to keep the miniature trees healthy.
It is easy to over-water plants in a small container. The surface of the soil may look dry while the soil beneath may be saturated creating conditions for root rot. To ensure drainage, mix gravel in along with the potting medium. It may be desirable or necessary to sterilize the gravel to prevent mold, an aggressive pathogen responsible for root rot, from endangering the plant.
Small gardening containers are also susceptible to drying out, than larger ones.
Using fish-tank water may provide the perfect source of nutrients for growing miniature trees. If the plants don't get their nutrients the root becomes root-bound in search for nutrients it can't find. Nutrients needed are in parts per million, and tap water provides an adequate amount of many plant nutrients.
Cutting into bark stunts tree growth, but it also damages the tree's health. The bark may not be cut all the way around, as this will kill the tree.
This is not practical since many tree species don't produce flowers. However it is a way of stunting plant growth as flowers use up a lot of energy.