Background and Cost:
This is based off of Free to Play Rank 23 to Legend in 3 days Day 80% win rate, but I changed it enough that I consider it a new deck.
This is a budget deck that only cost 1120 dust, and you can upgrade a couple cards to slightly improve performance.
Compared to the other deck, this one handles Contol Rogue, Evolve Shaman, and Murloc Paladin much better as they play a lot of weak cards that explosive traps can clear more easily.
Keep only one 3 card if you drew it and it is useful against the current enemy. Other than that, you need 1 and 2 cost minions and secrets, always keep 1 and 2 cost.
Examples for the 3 cost:
If you need to kill a key enemy (ex. Murloc summoning totem, Hunter Hyena, Mage Apprentice) Eaglehorn bow is universally useful at clearing key early enemy minions early on so keep that, otherwise try to get a Kill command, or Deadly shot
If you don't have those cards, Animal companion is the next best thing, so don't throw that away if you don't have the others, 2/3 times it can charge kill or taunt and block key minion and kill it next turn
If against an enemy who plays lots of early low health minions (Shaman, Rogue, Paladin, Hunter), discard the 3 cost cards unless you have Unleash the Hounds, or Animal Companion (hopefully buffs your low cost minions, or taunts). You really need, Explosive Trap or Alleycats to compete at the early stage with these opponents.
Essentially, just use cards that sync really well together.
Always play Alleycat first, provides board advantage.
Adapt 1/1 minions if you can or your hyena if you have 4 mana
Dire Wolf your 1/1 minions if you have them down already.
Explosive trap if you know your opponent is going to play lots of low cost minions.
If you can kill 1/1 minions to buff your hyenas, then that is the best bang for your buck (don't kill high attack/health beasts just to buff your hyenas, as it's better to have the strong minions attack others minions). Unleash the hounds is very useful if you can kill them right away or next turn to buff your hyenas. Usually don't play a hyena unless you can buff it's health at least once, otherwise, opponents kill it right away.
Animal Companion always a good 3 cost to play, unless you can do a combo with your 1 or 2 costs (such as adapting an alleycat)
Adapt strong beasts later on or weak beasts early on (if needed to kill a minion or keep your weak minion alive)
Tundra Rhino's Charge is sooooo great with Savannah Highmane if you need to kill a strong minion as your hyenas will have charge too. So if you place a rhino, and they place a strong minion, you know what to do.
Savannah Highmane is almost always a good card to play as even if it dies you still have 2x 2/2 hyenas
The final blow is usually using charge minions with Tundra Rhino (so try to make sure they can't kill it on the first placement), or using a weapon, Unleash the hounds, or Kill Command.
That's most of it, the rest of the cards don't need as much strategy.
If you beat 2 floors of Karazhan (1400 gold), you should replace Venomstrike Trap with Kindly Grandmother. Not a super key card but still helps when they clear your board with other minions or a spell