I do regular giveaways to raise awareness for STEM education and diversity in the tech industry.
We run month-long giveaways three times per year, usually April, July and October.
For shorter daily giveaways, typing the !enter command in Twitch chat is all you need, and use !claim within the time limit if you get chosen.
For the larger giveaways, use the !giveaway command for an info link to prizes, and how to use the !points command, etc.