Previously, I wrote a piece on tournament preparation in general, your goals in playtesting, the deck selection process and using publicly available data. I strongly recommend giving it a read as well in addition to this article. Today though, I want to focus on how to prepare as a team, what to focus on and get the most value out of working in a group, with some an insider view of how to test like a Magic pro team.
If you aren’t in a playtest group already, start by finding people with similar interests as you. There are brewers who are just interesting in building and winning with off-meta decks, players who just want to grind to top 1200 on the Arena ranking every month and some are testing for GPs, PTQs, bigger online tournaments and even big pro teams.
Whatever your goal is, I assure you there are a ton of other people with the same interest as you who are also looking to find some buddies to play with. Twitter is a good place to ask around and there are a lot of big Discord groups and communities where people discuss Magic decks and strategy and help each other prepare for tournaments. I also just changed my Discord (link above) to be exactly this kind of place where everyone can find someone else to play with, discuss Magic and prepare for tournaments together, so feel free to join!