1. Choose two colors you want to create the ombre effect. I would recommend colors that are in the same hue or color family but make sure they aren't too similar in color because the they will blend together and honestly, only you will be able to tell that they're ombre... yes.. sadly that was what happened on my first attempt.
2. Paint your base color all over your nail. 2 coats of polish would be ideal.
3. Once your base color is dry take your second color and paint from the top of your nail down to the bottom of your nail in light sweeping motions but stop the brush stroke somewhere in the middle of your nail. It helps if you hold your hand with your nails facing you and your wrist facing away because it makes the already awkward painting feel just a little less awkward and it's easier to make the sweeping motion. If you choose to hold your hand this way technically you will be now painting upwards. To all of you that I have completely confused I am very sorry!
Here's a picture to help you with placement of your hand: (Hint: if you have your hand placed like so, paint upwards toward your wrist.)
4. Once the second color is ALMOST dry take a clear color or top coat and in the same motion starting from the top of your nail drag down. This step will blend the two colors and create the ombre effect.
Once you get a hang of it you will find that it is a lot easier than you thought!! The better you get at this the more colors you may add, just repeat steps 3 and 4. I would limit yourself to three colors because the more layers of polish you add the longer it will take to dry and your nails will easily get messed up.
Another ombre effect that you can do that is a lot easier is the gradient. Take 5 colors in the same color family ranging in shades and start with the either darker shades and move to lighter or vise versa! You might want to make sure the colors are all in the same hue and are all either metallic, or standard or glittery. If you mix different types together you may just end up looking like a 5 year old gave you a manicure!