Manifesting your desires requires an understanding of the universe’s abundance and inherently giving nature. If you ask from a position of fear or desperation, you are sending out your fear and desperation, and the universe, giving, reflecting, and non-judgmental as it is, will send those right back at you.
Some find that they are content with little, while others find that they want much, much more. Still others create and manifest many things, only to later discover that it was the creation which brought them greater joy and satisfaction, more so than the actual possession or enjoyment of those creations.