Even though everything is well outlined in the video, I'll add the tools used, and cite the copyrighted stuff.
Also here's an img\text tutorial, in case that's more convenient.
1: join flagtrail Discord server, here.
2: register your account via the following command (just type it in #general chat in the server)
?register your-steem-user-name voting-weight-limit minimum-mana max-sp-for-engagement
So a proper command will look like something like this
?register imacryptorick 35 65 5000
Which means, my account will use up to 35% voting weight in flags (about 1.90$ at current prices).
No votes will be cast if my voting mana is below 65%.
And I will not flag anyone who has 50,000 SP or more.
Next you need to grant 
https://app.steemconnect.com/authorize/@flagtrail
Simple, yes?
Tools, and resources used in the video
@holger80's steemrewarding.com
April 6th 2019 posting statistics
April 27th 2018 posting statistics
STEEM's price chart
Value - Extract vs Create
@penguinpablo
@curie