Short – cram the maximum amount of meaning into the minimum number of words. There’s no strict guide to ideal word length, but search engines only care about the first 64 characters. Make every word count.

Clear – good headline are unambiguous. They must be immediately understandable in any context. Not everyone reading your writing will be a native English speaker. Keep this in mind.

Straightforward – use mainly nouns and verbs. Remember your nouns will be keywords for people using search engines.

Use simple words – short, Anglo Saxon words are best. Everyone knows exactly what they mean and they help you cram more meaning into fewer characters.

Active – use the active voice.

Avoid – forms of the verb to be. Articles ‘a’, ‘an’ and ‘the’ are space wasters best left out of headlines. Use a comma rather than the word ‘and’. Try not to use pronouns.

Plain English – there’s a grab-bag of short clichéd headline words that people never use in real life – such as nix, slam, rap. It’s better to stick with everyday language.

Some experts will tell you lists, questions and commands work well in online headlines. All may be worth trying, it depends what you are aiming for. Either way, they’ll work better if you keep my earlier points in mind.