The right voice and tone

For a really good guide on voice and tone, check out Voice and Tone by Mailchimp.

A few key things to keep in mind as a quick reference:

• Think about what issue you're trying to solve, are you teaching the user about something new, or are you helping them solve an issue? This helps you understand the users probable mood, and you can write to cater to that. Are they curious or grumpy?
• Keep the jokes, puns, happy remarks out of articles that are about solving issues. Your users won't be in the mood for it, and your pun won't be the magic sauce, just help them out
• It can be tricky, but try and keep sayings and colloquialism out of your writing if you're serving a global audience, you'll just alienate people and sound like you're a few roo's loose in the top paddock.
• Are you answering a question, or are you teaching something new? If you're answering a question, get the answer out fast. If you're teaching something new you can afford to go a little more long form since people are in a learning mode

One final thing to try and keep in mind with your content and in-app help that we recommend (which is contrary to some other systems goals), is this.

Do. Not. Upsell.

Nothing turns someone off your product more than feeling like they're constantly being mined for all their money.