I used a pen to do the little yellow dots in this manicure and it worked great for me.
I used Sally Hansen Sheer Strawberry (I know, I've been using this a lot) as a base color and L.A Girl Disco Brites in Disco Diva for the flower pattern. This pattern is from the BM16.
For the dotting, just put a drop of yellow nail polish on a piece of plastic or paper and use the pen point to do the dots in the center of each flower.
I really like this manicure, looks so pretty and summery in real life.