The markers and self watering brush

The self watering brush is the bottom item, you can gently squeeze the handle to get more water into the brush as needed.
The middle marker is Faber Castell, they come in a big fat variety and a more slendor one for finer work. They are watersoluble.
The Prismacolor markers are great, they have a dual end, one fine and one a fat brush tip...however they are alchohol based and do not blend.
I also use a white gel pen at times over dark colors, for lines.