Keep the artwork separate from the text, and number each piece to match with its caption. If the graph of other drawing is reprinted from another source, give proper credit to the publication along with the date on the caption sheet. All photos, drawings, graphs, etc. should include captions. The captions should be succinct and complete thoughts. The reader shouldn't have to refer to the article to understand the meaning.
Many people read only the captions and look at the photos.
The captions should lure them into the article. Type the captions on a separate sheet of paper. Don't attach individual captions to individual graphics. Give credit to photos and graphics. Mechanics Manuscripts should be typed, double-spaced and only long enough to cover the topic adequately.