Charge the last-hit with AA-W: stand where their farm step makes the wave carry your trade, because Sivir's lane pressure comes from taxing that minion touch with bounce damage more than from throwing early Qs on cooldown
Treat Spell Shield as the Sivir step—block the hook, bind, or setup spell that was supposed to start their lane, then use that exact moment to walk up and hit back, because E often grants contact instead of only preventing damage
In fights, pick the target that gives Ricochet a path through the rest of the team; Sivir looks strongest when bodies are stacked and games stay grouped, but real early gold holes still leave her short of the damage she wants later
Press R when it changes who gets to take the next few steps, not after everyone has already committed. In lane or river, that often means using it early enough to turn a blocked engage into your chase, or to make the enemy back off a wave they wanted to contest. In midgame skirmishes, use it as you and your support start moving, so the speed actually creates contact or denies theirs. In full fights, it is strongest when both teams are still choosing whether to enter, kite, or split. If you wait until autos are already being traded, you usually get much less from it.
Sivir gains a short burst of Move Speed when she attacks an enemy champion.
Sivir hurls her crossblade like a boomerang, dealing damage each way.
Sivir's next few basic attacks gain additional attack speed and bounce to nearby targets, dealing reduced damage while bouncing.
Creates a magical barrier that blocks a single enemy ability cast on Sivir. She receives health and a burst of movement speed if a spell is blocked.
Sivir leads her allies in battle, granting them a surge of Move Speed for a period of time. In addition, Sivir's attacks reduce her spell cooldowns.