If you want something, and you think about how you want it, you are sending a signal of "I don't have this but I want it." So the universe keeps delivering exactly that--a reality where you don't have the thing you want, but you still want it.
The way to work with the universe is to know what you want is already yours. When you have the desire, it is created by the universe. Any time you want something, just assume it's on the way.
But that can be difficult with us humans because we don't always trust the process of life. We don't always believe that what we want can come. So it's hard to stop thinking "I want this but I don't have it."
When we get stuck in that pattern of projecting "I want it but I don't have it," it's time to do a little work with the thought pattern. One strategy is to give what we want to ourselves. Usually we want all the things we do so we can feel love. So when we give ourselves love (through mantras, self-care, meditation, kind thoughts, etc.), we no longer are projecting "I want love but I don't have it." The vibration changes to "I am loved." Then once you feel loved, your reality can start reflecting that back to you in manifestations other than just you loving yourself.
Another strategy is "making peace with it never coming". Let go of the desire completely and truly stop caring if you get it. If you stop caring if you get it, then you stop projecting "I want it but I don't have it." Then the manifestation is free to come to you. One of my favorite ways to make peace with it not coming is to say "I don't give a fuck if I ever get ______!" If I can truly let go of the desire, it will come to me. This strategy can be frustrating because you receive what you want once you don't want it anymore--but that's the whole point, to feel good without the manifestation.
Above all, the best strategy you can use to get what you want is to feel good as often as you can. Take care of your health, express yourself creatively, stand up for yourself, laugh. When you fill your life with things that feel good, you can spend your time in the present moment enjoying life as it is, not needing change or manifestations to make your life better. And when you spend your time feeling good, you are a match to those things you want that also feel good. But you won't even care if you get those things because you already feel good!
That is the whole paradox: you must BECOME IT to SEE IT. You must feel good to manifest things that feel good. You must be the change you want to see. YOU are the creator!