After plant, the 40-second bomb timer ticks. Your job as Ts: prevent CT from defusing for 40 seconds. Your job as CTs: defuse OR kill all Ts.
T-side post-plant: spread to angles that cover the bomb from multiple distances. One in close (immediate trade), one mid-range (trade-frag setup), one back-distance (anti-flank).
CT-side post-plant: don't walk onto the bomb without info. The Ts are watching. Take a step at a time, listen for footsteps / drop sounds, smoke off close angles before defusing.
Both sides: nade utility matters more than aim post-plant. A flash before a peek is worth 2x your aim level.