I have done both things at different times with different people. Lately, after some recent experiences, I err strongly on the side of letting go of myself, abandoning any pretense, and trying to be unconditionally supportive. I would make some attempt to do that even if I were not especially close to the person. A lot of people tell me they don't feel comfortable extending themselves in that way and that is fine, but I have decided it is the ideal we should aspire to.