Three main factors that raise or lower EQR: position, suits, connectedness.
At the table, the more of the lowering factors stack up, the more you discount your equity. IP (acting after the opponent), suited and connected hands realize more, and OOP, offsuit and gapped hands realize less. Example: J♠ T♠ on the BTN is IP, suited and connected, so it realizes a lot, while K♦ 3♣ defending the BB is OOP and offsuit, so it realizes little. Weak-kicker aces and kings that get dominated, players still to act behind you, and pots with 3 or more players also lower it.