For a cutting, a good rule of thumb is to measure the across the top of the pot and then measure the size of your seedling from the visible growing section to the top. The pot size should be no bigger than about one and one half times the length of the cutting. Err on the side of choosing a small pot rather than a too-large one. If the pot is too big for a houseplant, the plant runs the risk of drowning when watered. Potting soil is a main consideration of any house gardener.
Many gardeners like to make their own potting soil.
Commercial soils exist, some particularly designed for certain plants, such as African Violets. I prefer to buy potting soil. That way, I know it contains the things necessary to good aeration and drainage, and I know it has been either baked or treated to rid it of bacterial pests. Once you ve potted your plant, you need to take care of it to keep it thriving. To do this, research the variety and place it in a spot conducive to its growing likes.