Hey there! All the way from Holland, so sorry for the bad English ;P I'm more with the handlettering, but now and then i'm making some projects like this galaxy.
I really like to use my Spectrum Noir Aqua markers for making my projects. An example you can see here:
Sorry for the dark photo's. It's quite late and don't have much light at the moment. This is my guide for de Spectrum Noir Aquamarkers:
And here are some pictures of my markers:
These markers are for sale in 6 and 12 packs, with all kinds of themes. Price varies EUR 9,95 - 19.95.
I also have some brushmarkers from Talens Ecoline:
These brushmarkers I use also for the coloring of my projects. Some people use the Ecoline Brushmarkers for Handlettering, but I'm really better in handlettering with a pencil and a fineliner :D
These brushmarkers are for sale per piece (EUR 1,87-2,25) or in packs (5/10/15, even 30 pack) EUR 7,47-59,95.
And final the liquid watercolor from Talens Ecoline.
I don't use these type very much, but it's like a childhood memory. In kindergarten we used this with some kind of crayon, but I really don't know how to do that anymore.
Really liked your lessons. Gonna search for "normal" watercolors :)