1. A de-consecrated church, bought on the cheap from the diocese during parish consolidation. Comes with small office and rectory. Good acoustics, ready to be dedicated to a new power, not exactly secretive.
2. A prepper's bunker. Terribly cramped. Huge supplies of food and survival gear. You keep finding weird shit that used to belong to the previous owner, who was an elderly and very Libertarian veteran.
3. School bus back in the woods. Not going to go anywhere. Blackout curtains on the windows. Still has the benches in it. Shelves and a couple hammocks suspended from ceiling.
4. Hidden room in the basement. False wall is good enough to fool folks doing a once-over. Nothing special, just storage space and a fold-out cot. If you don't own the house you are on good terms with whoever does.
5. Back room at a sleazy club. Someone among your group has the ear (for now) of a certain man of some repute in the underworld. Ask the bartender for a Tipsy Toucan.
6. Side room down in the service tunnels. It's a labyrinth down there, so getting in and out is tricky but you are unlikely to have any trouble: what's another unlabeled locked door down there?
7. Old abandoned house. The kind that everyone calls "The Spooky House". Technically owned by local eccentric with a nasty beagle who can sometimes be seen parked in the driveway. Whatever deal you have cut with them, it is hopefully worth it.
8. Isolated cabin up in the mountains. Tenuous cell connection at best, but no neighbors to worry about. Smokehouse, outhouse, woodshed. Lots of deer around. Travel to and from can be a pain.
9. Shipping container. As bare-bones as it gets. You can load it up on a truck if you need to.
10. Big van with an airbrushed wizard on the side. The classic. There are some inscrutable magics cast on it, so you can pull off some real Nico shit if you put your mind to it.