Check with your chosen journal to see what file format and resolution you should use, and whether you should put figures in the manuscript or keep them separate. Take extra care with digital images.
Every figure should have a legend below it, starting with “Figure“ and the figure number, followed by a caption. Figure legends are one of the more commonly read parts of a manuscript, so it’s worth spending time on writing the perfect legend.
If your figure presents data, make sure the legend includes units, and define any error bars as the standard deviation, 95% confidence intervals or other measure if used.