So because those of us that know the trick get asked this a lot in chat, I thought I would make a quick guide on how to do this as an easy reference for others.
How you vote more than twice a day(once on each site) is fairly simple. Instead of using your full name to vote, use part of your name. So for example I will use my name MrSnouzer; If I want to make an extra vote for the day, I will use MrS and then followed by MrSn for an additional vote. Both voting sites have a maximum of 3 votes per ip per day which is a maximum of 6 votes in total.
Here's the kicker though, it is based off of a glitch with their system so you can't expect it to be perfect. The name you are using to vote (in my case MrS or MrSn) have to be names of actual Minecraft accounts. So for me, MrSnouze does not work as a voting option as no one has that username in minecraft.
TLDR; Use Part of your name instead of your full name.