meditate, you could work on astral projection, and practice in the astral. there are many ways you can cast with it looking like normal things. a bath with sea salt can be purifying, but you could say you're having a bath. making a chamomile tea can also double as a healing potion. if things get really rough, find a place somewhere to have your circles [woods, park, ect]
that all being said, if you're following the wiccan path, you don't need to cast spells, circles, and so on to practice. take a walk through the park, sit in the yard [if you have one] make a bird feeder and hang it by your window. take 5 minutes every day to stop and look around at what we have. wicca is nature as well as wisdom. read, learn, study. these things, while they don't seem it, count as practicing your faith.