It’s hard to explain when and why to use certain cards, but it’s something that you learn with experience. Holding onto instants until the end of the turn of the person on your right is easier to explain: it’s so that you can hold your mana open incase you need to do something else, or change plans. I think something I get asked by newer players is why I hold onto board wipes for a few turns even when the field is pretty full, or board wipe when there’s only a few things on the field.
I have difficulty explaining how to properly use board wipes, mostly because it comes down to reading other players or having an understanding of how the politics are going at the table. If a player has just popped off but isn’t swinging, I’ll leave Rout in hand until they’re actually trying to go for lethal it. It gives me time to do other things instead of stirring them up; if I kill their creatures, they’ll get mad and come after me, ending my chance to stack my board against them. On the other hand, if my opponent has just cast Jin-Gitaxis and another has Sheoldred, I’m definitely going to board wipe. I don’t want to give the recursion player a chance to nab whatever just got dumped into the graveyard, and as a control player, I don’t want to lose my hand. While it’s easy for me to put things into words, and for you as a fellow player to understand this, newer players don’t always see it. It takes time to learn the behaviors of your opponents, and experienced players need to be lenient to this.
This brings us to the main point of the article: don’t be afraid to correct them sometimes. If you feel it’s fairly obvious that you’re popping off, tell the new player it’s time to board wipe. If they do it at a bad time, like when there aren’t any threats on the field, tell them to take it back. They’ll learn faster from their mistakes if they know they’re making a mistake. Be polite about it, though. Don’t scold them for making a misplay, just correct them.
Last time we talked about how I was teaching a friend how to play EDH, and I had to do this a few times. The most surprising one was his use of the card Cyclonic Rift. I think a common problem with newer players is that they have issues over and underestimating the power of cards. He used Cyclonic Rift to bounce my Clever Impersonator to my hand; at that point the Impersonator wasn’t a big problem, it was just a copy of Propaganda. The real issue is that he had over seven mana and I had a field of enchantments; me telling him to overload it cost me the game, but it brought to his attention how badly things can go for the opponent when you Cyc Rift midgame.
Hopefully this article clears up a few more issues you’ll encounter when trying to teach newer players how to play the game, but there will be more to come in the next few weeks.