The One Page approach:
This method of campaign construction is focused on creating something playable and rich, without cutting corners, but also without engaging in unnecessary labor. To that end, everything we make will be easily usable at the table. What then are we going to make? Primarily: timelines, note-maps, NPCs, and fact sheets (detailing adventures, artifacts, aliens, institutions and other disparate elements of play) - all of which will be scaled in such a way that everything necessary to game play will be contained on one page in each instance.
In cases where the subject matter is too broad to cover on one page, it can be broken into smaller components of a size more appropriate for one page. However, an overview page is often helpful, with component pages nested inside it, like Russian dolls. Maps provide an easy example; starting from the top down, I might make a map of the galaxy; a map of one of the planets in the galaxy; a map of a region of that world; a city in that region; and then down to a building within that city. At each level of scale I should be able to provide all the information necessary to use the map in play on one page.
Step One: Note-Maps
After, as we discussed in the previous entry, acquiring a hazy sense of your game universe's history and current (at the start of the campaign) state, it is time to begin to make something solid and playable. We will start with a note-map (see below for an example). Knowing about the theatre of action will give insight as to the sort of things that exist and go on in the universe. Below is the cosmic scale map I have worked up for my own universe "Earth ?" A cosmic scale map is almost more of an ideational diagram than a true map. The purpose is to throw down as many ideas as you can and scatter them through space; again consider the example.
As you generate your map, it may be helpful to work up a basic timeline as well. Each should provide ideas for the other.
The referee's skill as a cartographer is of absolutely no importance. Abstract scribbles will serve just as well as lovingly created color follies.
A word about fictional cities and the real world status quo. Fictional cities are one of the often derided elements of superhero comics. However, properly used wholly imaginary cities solidify and individualize the game world as well as the place of the PCs within it. For example, Gotham city is linked with Batman forever and always, regardless of context. NYC is linked with expensive cigarettes, Broadway shows and pizza. Further, do not fall into the trap of allowing your imagination to be constrained by real world geography, politics, or technology. The constraints of editorial mandate and long form story telling keep Reed Richards from changing the world; your PCs need not suffer under the same restrictions.
As stated and hopefully demonstrated above, these maps don't require any special skills or gear to make. If you can do circles and boxes, you can do one of these. However, some materials that might help:
Designer pens- I use micron; get a variety of point sizes. I suggest .5; .3 and .1
White plastic earaser- there is no substitute.
Whatever else strikes your fancy, really.
Homework: Read either Crisis of the Infinite Earths #7 for a specific example of supers universe history (likely at your library as part of a larger collection or comixology) and/or Fantastic Four 74-77 (on Marvel Unlimited/comixology) for a unique view of the Marvel Universe at many different levels, and an expansion (or contraction?) of the setting within setting nesting concept mentioned above.
Next time: a nested map or two, and time line creation steps/examples.