Summarize:

Use a cotton ball lightly soaked in nail polish remover to remove any nail polish currently on your nails. Gently trim your nails with nail clippers until your nails are at your desired length. Then use a nail file to smooth out rough edges and shape your nails.  You can also push back your cuticles using a rounded manicure stick. This will help elongate your nail beds, so your nails look longer. Alternatively, you can push back your cuticles using your thumbnail on your opposite hand. With ombré nails, your base color is usually a white polish or the lightest color you plan to use for the ombré effect. A white polish will help colors seem more vibrant, but using the lightest of your planned ombré polishes will give a softer, more subtle ombré effect. Paint this background color on all of your nails.  For an opaque base, paint two coats of your base color. Allow the first coat to dry completely before adding the second coat. To help your nails dry faster, it’s better to paint two thin coats of polish rather than one, thick and heavy coat of polish.
Clean up your nails. Apply your base color coat.