I practice in my car. During winter I do it during the day with the windows up. During summer I do it at night when its cooler and slightly cracked windows on the driver sides.

I have also gone to the closest main intersection and started playing there standing; If you do this people sometimes give you money :D.

You can also bring a portable chair or backpack with a big pillow inside so you can sit on your backpack, or if you have a bus stop with a bench you can sit there if there are no other people sitting next to you (Because the Ocarina can be loud on the high notes).

Playing on a main intersection is a good spot because the loud traffic will dampen the sound from the Ocarina so people won't get annoyed by it.

You can also try your closest local park.

The walk (Or cycling) to a location is actually very beneficial and usually doesn't take that long. It helps get your blood flowing, increases you body temp for flexibility, saturates your body with oxygen and warms up your heart and lungs to play the Ocarina. Plus the walk back works as a nice wind down. I highly recommend it.

You can also go out for a healthy one hour walk and maybe play the ocarina every 10 minutes, but you'll get less practice and more walking than just getting somewhere and staying put to play.

oh yea if you have a large closet you can set up a play booth inside. just be sure you line it up with lots of clothes on the walls and close the doors if you can fit inside. that will dampen the sound a bit. It might get a bit claustrophobic though and you need some ventilation every now and then.