"My question is, how do you get what you want? What's your crutch, your go-to or even just your most recent?"
I personally like to elicit the motherly instinct by complaining about how the world isn't fair. I throw big ass tantrums when I don't get my way, and am ready at all times to throw myself under the/a bus.
"There's NLP, taking advantage of the partial pseudo-science to elicit emotions, create frames or anchors and triggers in an attempt to persuade. You could take advantage of mental heuristics and ambiguous wording to trick them into a certain decision."
NLP is interesting stuff, but unfortunately the field is saturated with a lot of bullshit. This, for example, is pretty stupid:
Additionally, many people who developed NLP (such as Richard Bandler) were frauds and cons. Listening to Bandler work a crowd is great, and I recommend audio of his older lectures. But I wouldn't take a book developed off of his "theories" too seriously. However, there are some interesting ideas floating around in that field. Doug O'Brien's Sleight of Mouth was pretty good.