Build the first movement window
From game start through roughly 14:00, especially after a successful wave crash or when an enemy skirmish is visibly nearby; the three-Voidgrub camp is at 8:00
During the opening, use Q and periodic Colossal Smash hits to secure the wave without spending all mana on low-value poke. Choose a crash when you need a reset or movement window; if the enemy has stronger early pressure, take safe experience and let the wave come toward you rather than contesting every last hit. Around the 8:00 three-Voidgrub camp, move only after the wave is handled or when the fight is already visible and reachable. Your transition is a pushed wave plus enough health and mana to influence river, not a random walk into fog. When ahead, pressure the enemy's ability to leave; when behind, make each crash a chance to reset and recover.

Cho'Gath
Malphite
Nunu & Willump
Singed
Ahri
Alistar