Agreed. "warm and nurturing" is a great start. You definitely want someone who works relationally.

I really like Rive's list of straightforward questions. Once you make it past the email/phone consult stage (and think someone might be a good fit)- you can always schedule a paid consultation session- at which time you can get a little more into the nitty gritty of what you want to work on. And you can ask more specifically about what they consider to be the structure of how therapy should work (and/or what they consider to be the foundation of successful therapy).

When I did this with my current therapist he told me that all parts of me were welcome. All feelings and experiences were welcome (even if they had to do with him and/or the process of therapy). Most importantly, he stated that our relationship would be the foundation of the work. That was very different from how my previous therapist viewed therapy and the therapeutic relationship.

Not that one is better than the other, but my relational therapist is a far better fit for me and I've made immense progress with him.