There are some ways to do it:
1. You can mark yourself in lists of the topics bitcointalk.org
2. You can subscribe to some followers on Twitter in hope they will follow you back
3. You can post unique content and waiting for followers
All this ways need a lot of energy and time. And after all there is no any guaranty that all this actions will give you followers.
We have developed simple service for Twitter cross following:
https://www.bountyfollowers.com
How it works?
1. Go to https://www.bountyfollowers.com and login with your twitter account.
2. System will create a group of people for the cross following.
3. Follow all members in the current group
4. Wait until all the group follow you back
5. System will create new group of people for the future following. And process repeats again.
So with this service you can increase you twitter followers every day. We gantry you +100 new followers every week. There is no bots on the service!
Join us!
https://www.bountyfollowers.com
Is this legitimate? I mean those are real people that will follow you that care about cryptos?