This technique can be done with any colour combination, on both long and short nails. You just need to keep practicing your smile lines!!
Prep the nail and apply base coat - I use OPI's Ridge Filler Base on nails that need some smoothing, or you can use Lumos - another great product.
Apply a thin layer of white - in this case Alpine Snow - from the side towards the centre. Keep a small amount on the brush, and using a sweeping motion - don't be afraid to use the body of the brush, not just the end. Allow to dry slightly and apply a second thin coat. If you are comfortable with this, use more lacquer on the brush and just use one coat. Neaten up the smile line with the OPI Corrector pen, or with a cotton bud soaked in remover.
When you are happy with the shape and thickness of the smile line, apply the colour for the nail - using a sweeping motion underneath. Here I am using OPI's Strawberry Margarita.
Next, fill in the rest of the nail. This does not need to be too thick as you are applying two coats.
Allow to dry slightly, and apply a second coat - in the same way, making sure you blend in and different stoke lines.
Apply top coat. OPI's Rapid Dry is great, as is Lumos.
You can also use the same techniques with different thicknesses!
Anyways, just a different idea for you to try that can look really effective! This can be used on any shape and length of nail. If you are unable to paint a free hand line, you could try using tape, or the french line guides available in chemists.
Hope you have a great week! Please let me know what you think, and whether you want to see any more tutorials/guides.