Step 1: Build competent decks.
Notice that I did not say “Great” decks. I said competent decks. You do not need a bunch of epic and legendary cards to have a successful deck. What you DO need are:
1: Mana Curve: If you ignore the early game or the late game in your deck, you’re gonna have a bad time
2: Synergy: Having a great mana curve won’t really help if your deck is a jumbled mess of cards than don’t work together.
3: Value Cards: Acidic Swamp Ooze is a great example. There’s zero reason to take Bloodfen Raptor over Acidic Swamp Ooze in every deck except hunter decks. Likewise, you’re better off taking just all around good card like Harvest Golem or Chillwind Yeti over gimmicky cards unless you can REALLY utilize them.
Step 2: Follow the Metagame
Whatever the most popular deck is at the moment…play a deck that counters it well. You’re going to win more games that way. When the Meta shifts, shift with it. Play whatever counters the newest popular deck. If you keep playing decks that get stomped on by the flavor of the month and do nothing about it, how do you expect to win?
Step 3: Make the best plays possible
Start the game with a strong hand. Make efficient trades. Maintain board control. Know what the likely plays of your opponent will be (AKA don’t drop a bunch of 2/2s turn 6 vs a mage). Make efficient use of your mana whenever possible.
Do this and I guarantee you that you will start to win games pretty consistently. Players making bad plays with bad decks that ignore the metagame are the biggest thing holding people back in TCGs. Will you win all the time? Nope. Will you be a pro? Nope. But you WILL do MUCH better and will start to have much more fun playing.