I get hold of a plant pot, some wicking material, which can be hemp string, or toweling or whatever. A sharp blade and a plastic bottle. You need potting soil as well.
I stand the bottle in the empty plant pot, and then mark a spot some centimetres below the top level of the plant pot. I then cut two "T" shaped holes at that mark, on opposing sides to each other.
Cut two pieces of wicking material, each one being long enough to reach the bottom of the bottle on the inside and the outside whilst going through the hole.
From now on, I need only to check the level in the water bottles weekly. I leave the lid on to keep the mosquito pests out, and to reduce evaporation.
Having done that, stand the bottle inside of the plant pot, and gently fill that pot with your potting soil mix, making sure to leave the wicks up on top until you are nearly full, but below the wick outlets. At that stage, drop the wicks inside, and lay them around the surface area.
Saturate the lot with a gentle watering, and also fill the wicking bottle to overflowing. Let that sit until it stops draining, and then saturate it again.
Now you can plant your seedling into the pot. In this case, I chose two cucumber seedlings.