There’s no hard-and-fast rule here, but in general the bars should be wider than the white space between the bars.
Consider the following “Goldilocks” of bar charts: too thin, too thick, and just right.
With line graphs, since the focus is on the relative position in space (rather than the length from the baseline or axis), you can get away with a nonzero baseline.
When graphing data, a common decision to make is whether to preserve the axis labels or eliminate the axis and instead label the data points directly. In making this decision, consider the level of specificity needed.
When I have a table in front of me, I typically have my index finger out: I’m reading across rows and down columns or I’m comparing values. Tables are great for just that—communicating to a mixed audience whose members will each look for their particular row of interest.
Storyboarding is perhaps the single most important thing you can do up front to ensure the communication you craft is on point. The storyboard establishes a structure for your communication. It is a visual outline of the content you plan to create.