SmokescreenSmokescreen greatly diminishes the utility of an enemy champion that relies on ranged unit-targeted spells, such as Cassiopeia or Annie because vision of their target is required to cast these spells.
QuickdrawGraves can be used to dash through thin terrain. This allows Graves to be very mobile and can benefit him in chases and escapes.
Try to use Collateral Damage at the beginning of a teamfight when your enemies are grouped together, allowing you to hit multiple targets.
When the champion you are against has a blink (e.g. Ezreal), and he attempts to engage you, throw a SmokescreenSmokescreen to where he blinked, and quickly dash away leaving your opponent visionless.
By using smart cast, you can cast Buckshot and Quickdraw together in such a way that you dash back while shooting the three bullets of Buckshot in front of you. Use this combo to finish off enemies with low health and make a quick escape.
Despite being listed as a default recommended offensive item, Blade of the Ruined King is an ill-advised item to rush on Graves since Graves have relatively high AD scaling skills and the item does not give enough AD.
However, it synergizes well with Quickdraw as the attack speed it provides will help reduce the cooldown Quickdraw. Blade of the Ruined King is recommended when dealing with health tanks as Quickdraw allows Graves to use the passive effectively. The active effect is also useful in duels.
Also, save your spells until outside of SmokescreenSmokescreen as the vision loss can lead to the loss of your target.
If you are a champion that plans to cast a supportive ability on an ally, considering staying close to the ally so that SmokescreenSmokescreen cannot stop you from seeing them and thus casting onto them.
Avoid extended skirmishes with Graves as he gains armor and magic resistance as the battle rages on from True Grit. The bonus armor and magic resist can change an expected kill to a close call.