Organization of content

Margins

Regularly journals prescribe a margin size.

This gives a relaxed impression and collaborators can easily insert comments in the printed version of the text.

Justification

Left and right margins determine where a line starts and where it ends. In texts four forms of justification can be applied:

Left justification. Lines have about equal length (if not overruled by hard returns or manual line breaks). New lines are aligned with the previous one on the left side. Hyphenation can reduce the raggedness on the right side. Also referred to as left alignment.

Right justification. Lines have about equal length (if not overruled by hard returns or manual line breaks). New lines are aligned with the previous one on the right side. Hyphenation can reduce the raggedness on the left side. Also referred to as right alignment.

Centered justification. Lines have about equal length (if not overruled by hard returns or manual line breaks). The center of new lines is aligned with the center of the text width (space between the margins). Hyphenation can reduce the length variations of the various sentences. Also referred to as centered alignment.

Full justification. There are no leading and no trailing spaces. Unprofessional word processors, like MS Word, implement this type of justification by adding extra space between the words in a sentence. Professional desktop software, like Adobe's InDesign, achieve this by adjusting the space between individual characters, by adding (micro)spaces between words, and by micro-changing of font sizes. Hyphenation can reduce the variation in character density of the various sentences.

The La(Tex) family uses a reasonably professional form of full justification.

You have no control over the justification used in a professional scientific journal. You do have control if you are writing an internal report or a thesis. If you do have control, never use full justification the MS-Word way. Either do it professionally or use left justification.

Subheadings

You write to be read. To be cited. To be followed. To be criticized. Help your readers. Break your results down into bite-size pieces. Keep it simple.