I wouldn’t recommend learning to one-trick her because you actually need to know how to play other heroes for their ultimate (and to get it optimally.
Also, I don’t do vids unfortunately and I don’t have any recent comp game to give you a code for as I still have yet to do my placements lol
What I do recommend though, is constantly using your mobility to move yourself into the enemy back line. So that you can sneak behind them. I can also link my tips and tricks on Echo to hopefully help you
If you have anymore questions, feel free to ask.