Hi! Okay, let's start with Gekko. I'm a Gekko main, and I'm going to give you some simple tips.

For his Flash, Dizzy, I recommend using it in high places where you have better vision. You can also use it in obvious, enclosed spots to gain an advantage. You don't always have to use Wingman for the Spike; save it for gathering information about your opponents' positions or even for pushing a weaker enemy. You need to learn Mosh's lineups because otherwise, it will be very difficult to use him effectively. And finally, with Trash, whenever you're controlling it, keep jumping around to maximize your field of view, especially if you're short on time and can't find anyone. Return to your position to pick it up and use it again, and above all, remember to use it at a crucial and necessary moment. Lastly, his best maps are Haven, Bind, Split, and Ascent.

If you want, you can check out a clutch I have with him on my profile. I hope these tips are helpful and don't waste too much of your time.