Decide which type of landscape you want to emphasize. You may choose one or several depending on how detailed you want the map to be. Let us use mountains as an example to measure the height of mountains in different states, as well as the location of US swamplands and valleys.
Draw tiny symbols that represent a mountain, swampland, and valley. Perhaps use one mountain to show a shorter height, two mountains for a larger mountain peak, and three mountains for the tallest mountain. Feel free to be as creative as you want. You may simply draw each symbol differently to illustrate the size of the mountains rather than using the quantity of mountain symbols to alert the reader to the size. A similar method can be used to denote the size of swamplands and valleys, for example, with one swampland symbol indicating a small region enveloped by swamps and three swampland symbols indicating the largest area enveloped by swamps.
Draw an outline of your region. For the United States, for example, draw a plain outline of the continental US and lines delineating the borders of each state.
Draw a key to the bottom right or left of your map. The key is a small box that contains information showing the reader what each symbol means. In our example, the key will consist of the mountain, swampland, and valley symbols. Write the description next to each corresponding symbol(s).
Conduct research to see which states in the US have the highest mountains and which have lower mountains. Also research which states have swamps and which lands are dominated by valleys.
Draw your symbols on each state in the appropriate area, in accordance with the research you have conducted. The reader of the map should be able to look at the completed illustration and visually understand which areas have the tallest mountains, which states have swamps, and which locations are dominated by valleys.