Diagrammatic linework can be used to point out a detail in a story or highlight a caption. These strokes can curve or twist to connect the two elements together. Always use smooth arcs when drawing curved rules. Think of these arcs as circles that have been cropped.
If you know how to change a color, you know how to place a pattern. All patterns in the color process color palette have been created as swatches. To use the pattern, just create your shape and then click on the corresponding swatch you want. These are seamless patterns, so the pattern fills as you adjust the shape.