Perhaps you're a solitary who has to share your space with a non-Pagan roommate. Maybe you're living in a small apartment or renting a room, and there's just not enough space to celebrate a ritual the way you'd like. Don't worry -- there are plenty of ways to celebrate in a small physical space. From storing your stuff to casting a circle, here are some tips on how to make things work, whether you're working in a big space or a small one.
First of all, make sure you keep your ritual tools organized. Use a box or tub to keep everything in, so that it's not all scattered around when it's time for you to pull it out. Some people like to use the stacking drawers, available at discount stores, and dedicate a single drawer to each sabbat or season. If you have books, keep them organized as well, either by category or author. It will help you in the long run, because it means you'll be able to find things easily when you need them.
Keep things simple. If a ritual calls for an elaborate set-up, and you don't have the space, eliminate the bells and whistles. Use what you need, rather than stuff that just decorates or clutters. When a ritual calls for you to cast a nine-foot circle, and you only have four feet of space, cast a smaller circle. The specific trappings aren't what matters in the rite -- what counts is your intent and what you believe. A truly competent practitioner can perform a ritual with no accessories whatsoever.
Plan your decorations in a way that they'll have multiple uses. Select double-sided altar cloths that you can use for more than one Sabbat, or design an altar cloth which can be used as a storage bag. Use white candles on your altar, so you don't have to keep candles in a dozen different colors. Use paper and parchment for some of your rites, so that things can be burned and disposed of at the end of the ritual, rather than storing things for next year. Consider using a chest, cabinet or box as an altar, so you can store supplies inside it.
When it comes to actually performing your rituals, if you have a roommate, there may be some compromises to be made, and it all depends on how Pagan-friendly your roommate is. Ask your roommate if they object to you performing rites in common areas, such as the living room or kitchen. If they do, you may have to confine yourself to the bedroom. If they're okay with you using the living room for ritual, work around the roommates schedule so you can have privacy when they aren't home.
If you're in a dormitory or other shared-bedroom situation, things may be a bit more tricky -- again, it depends on how Pagan-friendly (or not) your roommate is. You may find yourself stuck doing rituals in the middle of the night in the bathroom -- and if that's the case, then work around it, or find another place to use for your ceremonies. Consider finding a nice quiet spot in a park, a place in the woods, or even borrowing a friend's place for a couple of hours.
If you're really stuck in a situation where you'll have no privacy at all, consider doing a "journal ritual". Rather than acting out the ceremony, write it down. Include chants, songs, poems, petitions to the gods, whatever you normally would have included in your rite. This is something you can even do with your roommate sitting in the room, and if any questions come up, simply say, "I'm writing about something that's important to me."
Remember, when it comes to Sabbat celebrations and other rituals, the most important thing is the meaning and intent behind it. Everything else is just icing on the cake, and can be done away with when necessary. Focus on what's in your heart and your spirit, and you'll be just fine, whether or not your circle is nine feet across or three.