The base colours, what I laid down were Winsor & Newtons Promarkers, mainly the blue so I would have a block colour to work from. Creating a skin tone that isn't a natural colour is actually a lot easier than it appears. Here, it was very easy to pick different shades of blue to create tones and shading.
For all the details then after, were Faber Castell's Eco Colour Pencils. I used the 48 set which was less than $15 and they blend surprisingly well for being so cheap for so many colours. I always start off with a light touch with the pencils, then press harder as I add more layering.
To finish the whole piece off, my favourite art supply, is the UniBall White Gel Pen. It comes in handy for a multitude of different art works. For this: it came in handy for highlights, inner eyes to create a more realistic eye appearance, and hair.
So, these supplies are cheap, cost effective and easily available to a wide range of artists, from starting out in art to professionals. They have good use and purpose. Try them, ya never know what you can create! :)