Been running a League since April. For transparency purposes, I've had ALL Juniors and 2 Masters. One of which builds competitive and shoots for regionals, one just wants to do Challenges, and the Juniors were all new to the game. I only run a Pokemon League with no intention of starting Challenges (between, schedule, anxiety, and stress). I'll throw my hat in the ring:
- Learn how to build decks from the contents of boosters
This is by far the hardest 'format' to build off of. Best advice I can give is to pick out as many colorless attackers you can and keep it to at most 2 colors, if possible. Which brings me to the next point.
- Make a deck or two for new players to use
Kids are going to come to you with all sorts of nutty stuff. Old cards from older siblings, theme decks, 18 booster-palooza. It's difficult, especially when they don't have any cards or have nothing to work with. It's best to have something pre-made and ready to go. I've been working on
THIS for the last several months. Despite that its Legacy, as it has about 90% of the games current game mechanics (I know it doesn't use a Stage 2, EX, Megas, or Prism Stars at the moment). Its best to teach them with a deck that goes along the lines of how something SHOULD be built, and not like how (most) theme decks teach ("Hau is best draw power!"). That said, if you want better theme decks, Mach Strike and the new Sceptile deck aren't shabby.
- Get ready to having to unlearn bad deck building habits
Kids and new players want to win with their builds, but they don't know what they don't know. And worse if they learn "playground rules". The hardest things to explain to kids is that they need Energy cards to do virtually anything (you can't play like its "Yugioh" and have all Trainers and Pokemon). Another is to correct the "20/20/20" deckbuilding mentality. It's a pain because it's close to decent deckbuilding, but not good enough (aggro decks = 50% of the deck is trainers). If you do get to the point to where you are explaining proper deckbuilding, also explain the 3 archetypes:
- aggro
- combo
- control
We won't get a good example of a combo deck until Unown DAMAGE is in English, but you can explain how aggro decks are properly built. I have a budget Wailord EX deck and a Sylveon GX control deck and I use them to explain that control builds are not built on the same "rule of thumb" as aggro decks go. Also, kids to not like facing AGAINST control decks, and understandably so. But they do like using them, which is pretty funny.
- Parents
From what I have seen, parents who ask questions and get involved will have their kids doing better as well. We had a kid and his two parents come by every week for a couple months and they got a full set of the Buzzwole and Beast Ring promos. The kid and his dad asked a lot of questions about deckbuilding and what to look for. Told him everything I knew, and now the kid cleans shop every time he shows up. Some parents just bring their kid(s) and don't pay much attention to whats going on and it feels like you're a glorified babysitter. It sucks when these kids want to do better, but they need their parents to help them and you're kind of stuck.
- Reporting
Reporting begins the last week of the month. It seems like the sooner you report, the sooner you get your League promos. If you don't report at the end of the month, you will lose your League status and it's painful trying to get it back quickly, especially because since Pokemon Support is really slow. Also, expect your League Promos to show up near the end of the next month. So there will be a gap between your first order and when you receive your 1st month promos.
- Scorecards
Your League may have a mix between competitive, casual, and newer players. The scorecards are by no means mandatory, but are neat tools to incentivize players.
- Extra mile
You may need to go out of pocket to help some players out. You don't need to do this, but there's some CHEAP stuff that can certainly help keep some players interested. I picked up a LOT of Jirachi Prism Stars for kids at the League. It gives them a way to earn a Prism Star card, and it can be splashed into nearly ANYTHING. I'd recomend that if you have a lot of new players/kids.
That's all I have at the moment, I feel like I forgot a few things, I'll keep checking back in.