I drink tea every day, and I want to learn how to bless my tea for certain things. Say, to think positive, or to be open minded. Things like that. How would I go about that without a bunch of ritual supplies?
Ritual supplies are not always needed.
Look up colored light or candles used for different spells with colors. Use those colors depending on what you need the tea for and visualize them before you drink it.
Example you want to fall asleep and have a nice rest so you choose chamomile tea. You then choose a mellow color like light blue or yellow. Take your hands and hold them over the cup of tea. Close your eyes and visualize that light becoming bigger and brighter over your tea, the light coming from your hands. In your mind concentrate on what you need it for while visualizing the light. When you feel ready finish with a "Amen" or "so mote it be" then drink your tea. White light is good for blessing anything and i use this method with white light when purifying my crystals or new objects. Do what feels comfortable to you.
You could use your own energy to bless it, just visualize a sphere of energy(of any color, whatever you want, depending what the blessing is for) and let it surround the tea or place it inside the tea and let it slowly disslove into the tea and visualize what you want the blessing to do for you. It's fairly simple but may take some tries. If you think about it, your magick(energies) are much like mucules. The more you work them out, the stronger they get.
You can also ask a god or goddess or a spirit if you have/believe any to bless it for you. Or use candles(extracting its energy into tea using your magick) or surround it with crystals to bless it.(Any color, depending on what blessing it is, also, research the crystals spiritual and energy properties. Knowing that can help. Example: Rose Quartz gives off loving and calming energies. And for candles: white, the color is widely known for purity and peace.)