Slack became a standard de-facto to communicate teams in IT area for sure. It has a lot of useful features as well as smart business decisions such HipHat acquisition.
Here is a nice article with seven points which help you to be more productive using Slack. My favorite tips are reminders and giphy. Plus ability to keep track of important messages.
Reminders are really excite. For example, to set reminder to notify you today at 12pm to come to the office just send this command to the slack bot:
/remind me to come to office today at 12pm
And Slack bot will send you notification today at 12pm. It’s also possible to set reminder for your colleague or channel as well as one time reminders or recurring ones.