For me it is pretty much totally "
case by case" and varies all over the map, and I have handled it in just about every way I can imagine in different cases.
The one overall "principle", if any, that guides me is that I try to be responsive to (my perception of) the SB's degree of comfort with the topic. This starts with reading her profile text carefully to see if it says or hints at her feelings about the sexual parts of a sugar arrangement. Many SBs say (in various words and ways) in their profiles that they are only interested in intimacy if and when some real attraction, "chemistry" (cue
@User#16452 the chemist!) and feelings develop and it emerges "organically" from the relationship, pretty much as it would in a conventional dating situation. Some, surprisingly many imo, completely and flatly rule out any physical intimacy in a an absolute/categorical way. (However, not ever SB who says that in her profile actually means it; I have been told by more than one SB in private correspondence that she puts that in her profile only to weed out SDs who are solely or too motivated by sex.) There are also many SB profiles that very clearly and strongly hint that they are offering intimacy; SA appears to prohibit them from saying it too directly (which would cause SA legal problems in places where prostitution is illegal, I suppose). And yet many more are simply silent on the topic. Beyond the profile, I look to the correspondence that proceeds the meeting and then to the conversation when we meet.
Unless she signals VERY clearly that she is comfortable with an intimate sugar arrangement, the one thing I never do is jump on the topic immediately or in a demanding way. And, perhaps too obvious to mention, I avoid being crude or rude about it.
Sometimes a discussion of the financial part of the arrangement, whoever brings it up, will trigger a discussion of the physical part too, though this is not ideal imo. Talking about each other's previous or other current sugar arrangements is another common conversational path to the issue.
Once the topic is "on the table", I do try to be very clear and direct but in a respectful and polite way, but occasionally when it doesn't come up naturally in the conversation, I just see what happens naturally when we go out...but that is a relatively rare circumstance for me.
-Ww