First piece of advice. Give in a little to get more. For example, you want to convince your friends to go to the place you suggested, but some are against it. Then you can tell them they can choose drinks, snacks, and even music. Everyone is happy with that.
But, in fact, the most important thing, the place, is up to you. After all, the food and drinks are almost always the same, and the music doesn't really matter. So it was not so scary to concede a little, but you got a lot.
The second tip is to find the upside for the other person. When you ask for something, when you want to convince, the focus often falls only on your benefits. You still have to show the benefits to the other person. You have to look specifically at that person, at their desires. For example, you need help with your summer house.
You do not just ask for help, but say that the person will be in the fresh air, will get exercise, which is useful, and so on. It will be in the sun, you can put music on. And after work you can relax on the river. And a person no longer chooses between: stay at home or work, but between: stay at home or work in the sun, with fresh air, get a healthy workout. And then also to the river. A different perspective.
A third piece of advice is to extend your time. For example, you're discussing renovations. Your significant other wants white walls, and you don't want to. You need to extend the time, that is, show what is to come. To say that white will get dirty, to remind them that a baby is coming soon, and white walls will fall into disrepair faster.
That is, you're immersing the person in the future, showing what's coming. After all, many people don't think about it, they argue here and now. Another example, when you ask for a salary increase, you have to say that in the future you will have more power. So the performance will be more, in the end everyone will benefit from it. There are a lot of examples.