Race or class or whatever, all of it matters to some degree, if you are talking serious Machivellian schemes in an office or whatever-- but a guideline to me is this:
most people or many people are so inherently selfish or self involved, that just being genuinely kind to someone, and not really expecting anything catches so many so far off guard, they will become your biggest fan. For the price of a cup of coffee. or offering to cover someone's whatever. Someone is getting lunch, offer to pay for theirs, if they are going out to get lunch for the group.
buy a coffee, get the next round, do so without expectation or sense of immediate ROI or pettiness about who paid for what.
most people or many people are so inherently selfish or self involved, that just being genuinely kind to someone, and not really expecting anything catches so many so far off guard, they will become your biggest fan. For the price of a cup of coffee. or offering to cover someone's whatever. Someone is getting lunch, offer to pay for theirs, if they are going out to get lunch for the group.
buy a coffee, get the next round, do so without expectation or sense of immediate ROI or pettiness about who paid for what.