The intended way is having fun. For me, it means creating FFAs with 9 cards from every card type/ turn (you can't click discard all when you have less than 10 cards from a kind), 0 card limit. And then surrendering when the game starts.
However, if you are having fun by winning games, I suggest joining a clan and do lots of sparing matches.
Join by finding a good clan in
https://www.warzone.com/Clans/List and then send PM to their recruiter.
https://www.warzone.com/Clans/Join is a trap - the best clans don't recruit this way.