When you're just starting a business or a startup, most probably you'd have very few resources, and to succeed using these scarce resources, you should go for win-win situations.
Most people only focus on wining, and this is a very bad approach, if you're the only one wining in a deal, probably you didn't win, because this person won't came back for you, which means you've actually lost that person, and maybe forever.
Always focus on giving more value to your customers, team, suppliers or simply anyone who is dealing with you, because that is going to be the way you win people, and if you win people then you've won as a business.
So win-win situations can't be just compressed into a single example, but I'll try as much to illustrate what I mean.
When we were dropping one of our first products (At a company that produces dietary supplements) we had very few resources, and we needed to spend every single dollar carefully, so I just called a startup that delivers products to houses, and I made a win-win situation for them.
I said: "I'll create a marketing campaign that is dedicated for you only, marketing my product on their platform and providing the links from their store, and in return you would post my product on your facebook page "
So they approved my request, as it will add value to both of us, I'll be exposed to their fanbase, and they'd be exposed to people who will view our marketing campaign.
So win-win situations have so many ways, but it goes as something alike.
What you need to search for is people who are almost at the same phase you're at, if you're just starting out then find people who are also just starting out, if you're an established business then search for established businesses.
Also find people that have aligned goals, like in the example above we both needed exposure, and that way we could help each other with it.
You might for example make a marketing campaign that features you and a supplier, and make him pay for the advertising costs (As you've made the marketing campaign so you've also contributed)
Before you think about what value you could gain, think of what value I could provide to people I'm trying to make a win-win situation with, and what should make them approve my request, and if you do it right, most of the times you'll end up with done deals.
So I really hope that was helpful and that you've actually learnt smth from it, and that my message was clear enough, I wish you great success in life, and thanks for your precious time.