Pick a direction in the first three rooms
Roguelike power comes from synergy, and synergy requires commitment. When the first upgrade offers two paths — fast and weak, or slow and heavy — choose one and take every later pick that supports it. A run with five unrelated strong upgrades loses to a run with four upgrades that compound.
Learn the offer pool
Each of these games draws from a fixed pool per act or biome. After a few runs you can predict roughly what will be offered, which lets you plan two rooms ahead. In Hades that means knowing which gods favour your weapon aspect; in Slay the Spire it means knowing which relics will pay off an attack-heavy deck.
Thin the deck
In deckbuilders, a smaller deck draws your best cards more often. Removing a weak starting card is frequently worth more than adding a mediocre new one. Shops and removal events should be evaluated first, before the shiny card.
Spend currency on permanent power early
Most roguelikes have a meta-currency that unlocks new items or permanent stats. Early on, spend it on breadth — new weapons, new cards, new characters — because each new option expands the pool of runs that can succeed. Save the narrow upgrades for later.
Take the harder path when you are ahead
Risk modifiers — elite fights, cursed chests, higher difficulty doors — pay out proportionally. If you are healthy and your build is online, take them. If you are on your last life, take the safe route and live to compound later.
Death is data
After each run, identify the turn or room where it went wrong. Usually it is a single decision: an upgrade you took against your build, a fight you entered low, or a resource you never spent. Roguelikes are decided by a handful of moments, not by average play.
Balatro-specific: protect the multiplier
In Balatro the ordering of jokers and card effects decides the score. Read which effects are additive and which multiply, then arrange so multipliers apply after the additive bonuses. Check the in-game run info panel for the current order rather than assuming it.
Vampire Survivors-specific: plan the weapon slots
Weapon slots are the real constraint. Decide which weapons you are taking to full evolution before you accept pickups, because an un-evolved weapon occupies a slot that a completed one needs.