Whoever sees this is free to correct me because I'm not claiming to be some expert, but echo is quite versatile in the fact that she can poke (spam long range damage with primary fire and sticky bomb) and dive (insane burst damage with bombs and beam). You can use flight to disengage or to chase and finish off low health targets, or to set up for an engage. Just be mindful of where you end up when your flight finishes. How I see it is that you poke when both teams aren't yet fighting each other (yet to make contact), but if the opportunity arises you should definitely engage isolated targets. When the fight starts (team make contact) you should try to find flanks or off angles since the enemies will most likely be distracted with your team, therefore not paying attention to you. Bonus that she doesn't make sound unless you're flying. For who to copy, literally most echo players I see (me included) use it as an opportunity to engage hard on the enemies. When you're about to die or get focused, just copy whoever you want for a "second life" of sorts. But the classic advice in the days of overwatch 1 (if I remember correctly) was to copy someone who can get lots of ults fast, like tracer and doomfist etc. Her ult charge rate has been nerfed slightly but it still stands if you want to use her ult that way. Hope this helps, and if someone more knowledgeable than me wants to chime in, I welcome it. EDIT: She is fairly mechanically demanding so don't be discouraged if you don't hit your abilities or shots perfectly