Sometimes playing dumb will reveal a lot about people, ie, the dumb blonde in disguise of the nerd thing. Or acting coy maybe.
I'm usually direct and calm and show people I'm not there to razz them, just present something so they understand it clearly, and thats all you need usually.
So, you sandwich a difficult conversation, by giving good news, bad news, then good news and it softens the blow.
Customer service, smoothing tempers, calming irate people, I guess those could be considered manipulation tactics, to calm the beast.
Present an issue, then present the solution so they don't have to think about it and it is helpful. (Being overly helpful, or affectionate in order to be seen as nice or kind).
One thing that backfires is offering anything for free to friends. (amazon gifts, eft transfers, etc). I guess people don't trust gifts even if it really is just a gift with no expectations in return, it flips some switch like an alarm and it isn't justifiable. That kind of social rule between genders is not 'loaded' sometimes its just simple gifting.
I'm too avoidant to want anything in return anyway. Or, a gift is a show of affection and thats all it is. I think. Or maybe I need to separate gifting with affection, as it might get weird. But I've found a group called Buy Nothing where you can gift strangers with things and it is normal to gift in that setting, and a lot of lonely people love it because you can get out of the house and see other houses and just say hello and its something to do in the pandemic that people like. It also saves a lot of things from going into the garbage.
You just show appreciation for little things and it warms the hearts a bit. Its not manipulation, but maybe a needed interaction that fills the empty place. But gifting is probably a little bit of a type of manipulation, I guess, have to think about that. Perhaps its a way to win someone over or bond in some way when you don't feel worthy of them. Hmm.