1) There will be a box on each voting site where you can put in your Minecraft username. Entering your Minecraft username exactly as it is shown in-game, with capital letters and everything, is required to receive your rewards. 2) After you have correctly typed in your username, you are required to complete a captcha to make sure you are a real person, such as clicking to box to verify that you are not a "robot." 3) Once steps 1 and 2 are completed correctly on the voting sites, click Vote which is usually below the captcha. 4) Vote again on each site after 24 hours have passed.
CathalPoints from Voting
In order to receive CathalPoints, you must add your Minecraft character to your profile on the website. To do so, sign in on the website and go to your profile. Click the "Characters" tab towards the left of your profile, and then click "Add Character". Select Minecraft as the game, and then follow the instructions it gives on how to verify your Minecraft character.
When voting offline you only get rewarded for one vote when you log in. So if you vote all three times while logged off, you will only be rewarded for one vote when you next log in.
Here is a video which shows how to vote on each voting site: