Customizing has no real 'quick fix' its pure a personal preference thing. So what I recommend is going into the brush settings and just play around with everything until the brush gives you a nice feel / result. So; I differ between brushes with pen pressure and no pressure and things like flow, dual brush, texture etc. When I find something that works, I use it - if not, I keep experimenting
Most of it is done with the default chalk brush from the Dry Media Brushes pack that comes with photoshop. You can load it by going to the brush menu and pressing the little arrow in the top right corner, in the drop down box there are some brush packs, the dry media one is one of them. Then I use the standard size 40 size chalk brush. It's a tricky one to work with but I really love it.