Thanks man! Usually i will airbrush one color on. In this case i airbrushed the skin color on. Then I move on to the other colors starting with the color that will take up the most paint which was that dark blue and so on. I also use a really fine brush to draw an outline with paint for example the white and green areas on Lockon. I will then go in and fill in the color with a thicker brush. I mainly use two brushes:
this is the thicker brush https://www.amazon.com/Mr-Brush-Round-No-Mr-Hobby/dp/B002DTFCIQ
and this one for the details https://www.amazon.com/TAM87172-Tamiya-Modeling-Brush-Pointed/dp/B00VTDYF8K
The tamiya brush is super fine, i think it would work better for you instead of a toothpick. I used to use a toothpick myself for the little details but its much easier with a brush. For paints I use Mr Color paints. Usually a drop of paint with a drop of mr color leveling thinner would be enough to get somewhat of a smooth finish on the figure.