This was made digitally, but I learned the most important skills from drawing on paper. Not having Ctrl+Z to lean on has a way of making you learn from your mistakes! I'd definitely recommend getting some pen-and-paper practice in. I don't know how much you've worked with them, but here's some tips just in case:
Printer paper is cheap and as good a medium for pencils, pens, and ink as any pricey sketchpad.
A mechanical pencil is a mechanical pencil, no matter how fancy it looks. BIC brand mechanical pencils have great-quality lead and erasers, and are cheap.
Remember to not touch your pencil erasers! They'll get your skin oil all over them and when you use them, the oil leaves graphite smears that won't come off.
Quality colored pencils are worth it, as are quality inking pens.
You can get a wide range of colors out of minimal materials if you mix colored pencils and inks! A set of 12 Copic markers and a set of 24 Prismacolor pencils will give you a lot of colors to work with if you mix them together.
When mixing colored pencils and inks, it pays to make a palette to refer to later. It takes time--you'll have to lay down each of your pencil colors for as many markers as you have, then color them over with the markers, and list what pencil and marker you used beside the sample. It's super-useful, though, and keeps you from making mistakes from guesswork, and from wasting pencil/ink mixing them together every time you want to test a color mix.
Another thing, try adding patterns and textures with your colored pencils before inking them over! It really helps breathe life into the work.
Hope some of that helps!