To start off, make sure you've got everything ready on your table, container of clean water for dipping your brush, kitchen towel, water based acrylic paints, brushes that you want to use etc,
not forgetting the most important thing...
your mug of tea or coffee

Mix your paint with a cocktail stick to ensure the colour is even. Decide which brush you want to use, I chose a brush with long bristles to get a nice line of paint on the nail. Dip your brush into the water, dab off excess onto kitchen towel then dip the bristles into your chosen colour of paint.
I used white as it shows up well on the red enamel.

Start at the corner of the nail, bring your brush down onto the nail at an angle and gently but quickly sweep the brush across the nail, lifting the bristles away when you've got the desired look.

 

You can repeat this as many times as you like and use different areas on the nail.

 

Don't worry if it looks slightly untidy (as mine does), you can cover that up later

 

Next you might want to add a few dots, I don't have a dotting tool so I use a short bristled brush, you can also use the end of the brush handle if you want to.
Dip the brush into water, then into your chosen colour of paint, again I used white so you could see it properly.
The dots on this nail aren't 100% round or perfect by any stretch of the imagination, but when you're learning it doesn't matter, art is in the eye of the beholder (that's my excuse and I'm sticking to it lol)

 

When you've finishing titivating the nail with paint you can finish it off with some rhinestones, this not only looks pretty but it also covers up a multitude of sins where the flicks aresn't neat at the ends
Apply a generous application of your chosen topcoat, inset the rhinestones, wait a couple of minutes then pop on another application of topcoat and voila, a nailarted nail.