I like to start with writing out my intentions. I make a list of things I want to manifest, then set to work. Vision boards are great to give you a visual reference for your dreams. Your vision board can have photos of cars, homes, dream holidays,etc. on it. Whatever you like.
Then, check out manifestation guided meditations on Youtube. Remember, to focus on what you want, not on what you don't want. Express and feel gratitude for what you have, spread light and love to those around you, and visualize your dreams coming true. Envision every sensation--smells, taste, touch, sound, etc. Really feel yourself living out your dream. Then, let it go, knowing the Universe will bring it back to you.
Best of luck and happy manifesting!