The first step is to figure out if you actually need to use end-of-line hyphenation (EoLH).
Depending on what you're writing, you may not need to use it at all. Internet publications, for example, don't tend to use it, even when the lines are short. Here's part of an online article (which is especially narrow as it is used next to a photo) as it appears on my screen:
Rhett Nicks, director of the
animal shelter, told NBC-
affiliate WCMH-TV that there is
a chance the dogs, named Polar
and Bear, may be put down due
to the severity of the child's
The page is responsive, which means where the line ends changes on screens of different widths. There are several ways you can have EoLH on a webpage, such as shy hyphens, but usually it's not worth it.
In addition, sometimes typesetting is not your job. If you're submitting your writing to someone else (such as a journal) check to see what their policy is. Don't do work that you don't need to do! (Even if someone else does the hyphening, you will likely want to proofread to make sure it looks good.)
Otherwise, most writing software will have an option for EoLH, which can help you get started. You definitely want to proofread automatically generated hyphenation.
Your style guide will tell you how to hyphenate (if you don't have one or it's not specified, you can follow a style guide that does have such instructions).
For example, one style guide, largely (or entirely) based off the Chicago Manual of Style, says the following:
- In general, follow the intraword dots in Merriam-Webster’s Collegiate Dictionary.
- Don't end more than two lines in a row with EoLHs.
- The hyphenated word should have two or more letters at the end of the line and three or more at the start of the next one.
- Some words, like "par·tic·i·pate" have a syllable in the middle that is just a vowel; it should go before the hyphen (e.g. "partici- <newline> pate").
- Divide words at natural breaks, such as between the suffix and the rest of the word or between halves of a compound word
- Avoid hyphenating proper nouns.
- Lastly, if following the above results in something ugly or confusing, modify it so that it's not either of those.