Single stones or crystals can be great for energy work with the chakras, as in chakra healing, and aura color alignment and aura balancing.
Single stones or crystals can add metaphysical energy to your feng shui fountains, or any other water fountain. As the water passes over the rock, the metaphysical energy of the crystal is released into the atmosphere. This can be used for healing, stress reduction, prosperity, love, you name it. The stone makes the difference.
You can break the crystals or stones up into a powder and blend the powder in with your incense, to empower the incense with the stones quality.
You can charge your stone with intent, and carry it, to help you to manifest certain qualities, like health, prosperity, or love.
You can add gemstones to oils that you wear, to help infuse the oils with the stones metaphysical and magical powers.
You can add stones to your dream pillows, and sachets.
You can take a stone with you into your bathtub, to impart the quality of the stone to your Magickal Bath.
Many magick spells can call for a particular rock or crystal. In magick spellcrafting, you may need to sleep with it under your pillow, use it in a bath, place it in the center of some special colored candles, place it on your altar, or even meditate with it.