Imagine the situation: you need to quickly get consent, but there is no time for persuasion.
What if there is a way that works almost instantly?
Psychologists have long studied how people make decisions, and it turns out that the key to success is not in long conversations, but in the right start.

One of the most effective techniques is to use the “anchoring effect.” This is when you set the tone of the conversation so that the other person unconsciously begins to move in the direction you want.
For example, instead of asking, “Will you help me with a project?” say, “When would you prefer to take on the project—this evening or tomorrow morning?”
This way you immediately assume that the person agrees, and all that's left for them to do is choose an option. Their brain automatically focuses on the solution, not on doubts.
Another trick is the principle of scarcity. People tend to want things they perceive as rare or temporary.
If you say, "This offer is only valid until the end of the day," the other person is subconsciously afraid of missing out on the benefit and agrees faster. But it's important not to overdo it - false urgency destroys trust.
And finally, mirroring. Repeat the pose, intonation, and even the breathing of the interlocutor. This creates a sense of kinship on a non-verbal level, and the person begins to see you as “one of their own.”
For example, if he sits relaxed, leaning back in his chair, do the same. If he speaks slowly, slow down your speech. Such synchronization lowers the barrier of resistance, and your request will be fulfilled more willingly.
But remember: these methods only work if your goal does not harm the other. Manipulation for profit will sooner or later destroy the relationship.
Use psychological techniques to find compromises rather than win unilaterally.