A Lamy Safari (medium) and a tin of Faber Castell Polychromos pencils. The Lamy is the best fountain pen I’ve ever used. It’s affordable, easy to find, has a great line and never clogs. The pencils cost more than the pen, but they’re worth it. Nice, soft blendable colours means you don’t need that many different hues. Be sure to have a sharpener specifically for colour pencils though, or they won’t last long. These Polychromos fellas are the nearest thing to my much loved and much missed Karisma pencils.
Oh, and some paper. Preferably cartridge, quite thin. Or a Leuchturm1917 notebook.