I went for a somewhat fantasy themed look with the vibrantly coloured cactus and aquarium castle statue however it's up to you how you want it to look in the end. When planting, ensure you lightly compact the area around the plant to enable the roots to set and receive nutrients. Avoid planting against the glass as plant roots don't like sunlight. If using cuttings, dip the end in water then rooting hormone before planting to improve it's chances of survival. After you've finished, water them in and leave the lid off for a few days. You would normally water very lightly and adding the lid immediately would make the jar humid.