You can get free Bismuth on our Discord and join channel #pawer-bot. Register your address and soon enough you may be lucky to receive a free air drop.
Another opportunity is participation in free Bismuth giveaways on Twitter. When you tweet about Bismuth and register it on the blockchain, you will be rewarded after reaching a certain amount of users. Restrictions apply.
One other opportunity is joining the developer community on GitHub. After contributing valuable content, you will be eligible for a reward, which is usually much higher than any of the previous two.