The best training course that I ever attended, when working at Hewlett-Packard, in the 1980s, was a course called 'Collaborative Negotiation'.
It has helped me enormously, over the decades since!
The essence of Collaborative Negotiation is to understand that negotiation is not a 'zero-sum game', where the 'win' of one party comes only at a 'loss' to the other. This is not true, a good negotiation ought to be a win-win collaboration towards the best solution for both parties.
The first step to using Collaborative Negotiation is to understand that everything is a negotiation and everything is negotiable.
The main route to success is for both parties to do their best to understand the motivation, needs, both tangible, and emotional, and use that understanding to find novel, unexpected solutions that meet these needs for all parties.
This requires work, imagination, and emotional intelligence - practicing negotiation every day, whenever the opportunity arises, helps build these skills.
Whenever you are presented with a situation that doesn't seem ideal, realise it is a negotiation and try to understand the position of the person you are working with.
Then you, and the other party, can frame the situation in a way that makes more sense, and, from that, work towards a solution.
The practice of collaboration, and the importance of negotiation is the core of my book Collaborative Consulting: Service Management Scenarios.
If you are interested in having things work out better, but don't feel comfortable bullying others, or tricking them, or using confrontation to get your own way, I strongly recommend the book to you.
https://www.amazon.co.uk/Collaborative-consulting-service-management-scenarios/dp/0113313918
