A bit of everything…
This one was done quite a while ago, with my nail art pens.
I find with picture-nail art having a base coat in a very light, natural looking pink always works best. As for how to, take your time, look at the pictures and work in layers – plan out what is going on what nail first!
Here are the inspirations I used for each nail:
Moustache (for Movember): http://www.youtube.com/watch?v=6wc66W0lYx0&ob=av3e
Hello Kitty: http://www.youtube.com/watch?v=SdHlNMPFr_Y
And the little frog thing: http://www.youtube.com/watch?v=QbKW-ldunzM
With the pens I found the hardest part was waiting for each layer to dry and not smudging them! However, I bet you could try this with a paintbrush, give it a go!