I was inspired by another nail technician to do this design.
After you apply base coat on the nails with detail brush make the smile line of the French.
It is made by using flat brush and one stroke technique. With the two corners of the flat take two colours, one dark and one bright. Paint the tips. After it is completely dry, apply a glittery top coat on the tips only.
I reckon it is lovely French on its own, therefore you can leave the nails without any design.
Anyway if you decide you can paint some flowers, or whatever....
On the thumb and ring nails I have done white flower, and added some purple and black lines inside the petals. Outline the petals with black paint.
Make the gold stamen of the flower and some black wavy lines above.
Do not forget to seal it with topcoat. I always use Seche Vitte fast dry top coat.