If you like me, and you buy cheap, you might also end up with a cheap monopod in usage with a ricoh theta. And if you like me you find the tripod mini base of such an investment less than helpfull. (The goal is that it stands more than a few minutes without beeing held, for shooting a pano without the "me" in foreground).

After watching an unrelated video I came up with the idea to use a mini tripod with expandeable legs as a base. This is how the setup looks like:

First of all, I wouldn't put something heavy on such a setup, its not stable enough for a dslr.
Second I recommend to use an additional sturdy ball head as the base for the tripod, so you can level out (=not tipping over).

As you can see in the title image the whole setup is small enough to be carried with the regular equipment. (Btw the cheap silicon covers for the theta is also a recommend)