It's decided: absolutely no cuddling of any kind (or, for that matter, hand-holding, which to me is more intimate, or kissing beyond maybe a peck goodnight after a couple of dates) until I've hung out with or gone on dates with someone at least four times prior. If I'm still interested in developing a friendship or relationship with someone after that many times with no real physical affection, I can be fairly confident the relationship (friendship) is probably off to a genuine start, and I've had time to assess what kind of relationship/friendship I'm interested in without muddying things with sexuality or creating false intimacy or a misleading sense of harmony born of physical affection. And no, I'm not interested in sexual gratification without a relationship, so that doesn't apply to me. And I've also had time, by then, to figure out whether we have enough of a "real" connection to merit the trust and affection of physical intimacy, or whether I'm just horny or needy at the time. That's not to say I can't spend a whole evening with someone and form a connection that would merit some (basic) physical affection, but waiting lets me really assess with a clearer head, I think.
And let's be honest: if someone is still interested in hanging out with me after at least four times of little hope of getting any action, even in the form of cuddling, that's an indicator that they probably are genuinely interested in me as a person. Of course, some are remarkably patient, so it would also depend on how often we hang out, how persistent they seem, whether I'm feelin' it, etc. And it could backfire: I might unintentionally send the message that I'm not a physically affectionate person, which I really, really am in certain friendships and in romantic relationships. But I'm not very concerned about that.
Ugh...I'm not big on hard-and-fast rules, but sometimes, you've gotta just draw a line somewhere to keep yourself reminded and level-headed. I'd kind of made this rule for myself loosely but have fudged it...and I've never looked back and thought fudging it was a wise decision. Not once. Maybe I'm learning. This rule is now firm. ...er.