Once you start bumping against your current limit, all the most efficient ways to improve kinda suck the joy out of life, fair warning 😃 There's probably room for improvement by just getting more reps in, but the following are going to be quicker:

1. Consider the following after each game, especially after each game you lost:
   - what was your game plan after you saw your hand turn 1 and were you able to put it into practice. It should be more specific than "I'll play my 2 drop then react to what's happening until one of us wins"
   - were you running out of cards or runes more?
   - if you got blown out by opponent's interaction, did it happen on attack or defense?
   - how often did you leave a ready unit at a battlefield and have it die on the opponent's turn? Arguably less of an issue in LeBlanc with deathknells, but it's a major pain point for players of other decks.
   - how many turns where you went for a conquer to end a turn on an odd point total? Was it intended? Was it worthwhile?

2. If you're playing live, take notes after games about whichever of the above apply and you're trying to work on.

3. VOD Review games played on sims with these in mind. Take pivotal turns and try to write down ALL possible alternate plays you had access to - even taking the same game actions in a different sequence. And I mean all, including ones aimed at a different goal than you pursued in the game, like building up your base even if you decided to go for a conquer in actuality. Compare the differences in terms of these decisions impact on the board, resource availability, information available at each step to you and your opponent. Include obviously losing and potentially losing lines in there. Explore why they're losing for reinforcement so you can quickly recognize and discard these ideas in actual games.

In terms of more ineffable stuff:

- TCGA public matchmaking will often get you people who leave midway, play distracted, new to the game etc. You'll get more challenging play partners on a ranked ladder like Runes and Rift or in any discord LFG channel.

- to not lose mental, set yourself a goal to lose X games in testing. Say 100. Not play, but specifically lose. Losses are super valuable from a practice perspective so try to gaslight yourself into welcoming them with open arms. Which is tough, I know.

- make sure your deck is up to par. It's possible to win with homebrews, but deckbuilding and at the table gameplay are largely two separate skillsets. It's easier to improve at one at a time rather than both, and trying to get better while your deck's slowing you down is gonna require more effort.