The verification is "memetic biometrics" so you have to spend time with the other pseudonyms (of course, how or if people verify one another is entirely subjective, the idea is that it would be a trend or norm to do so, as the network becomes associated as in-group and there is reciprocal altruism. )
You need to have NYM to register, and NYM is burnt unless you are verified (or, re-issued after every pseudonym event) so, if you manage to get a couple of NYM and register in multiple parties, you would probably not get verified in all of them but 1 (and, be paying the network, as in all NYM holders, for the possibility. )