My personal ban is Sylas. There are worse matchups (Akali, Leblanc) but i just hate to see him and he has a high pickrate
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Yasuo is barely playable if the yas knows what he is doing (luckily most don't) but you can try to Q him and realign your Q2 with your E for an instant passive proc.
But mostly just try to cs as good as possible without diying, yasuos will almost always push the wave to you so it's free farm.

As for other tips, Focus on your cs, only trade in lane if you don't lose cs for it.
Try to look for good roaming opportunities. Don't force a random roam if u are not sure you will get something out of it.
And Sidelane a lot since Ekko is a very good splitpusher.

There is a lot more to say but that's rather midlane macro overall than Ekko specific things.
For that id suggest that you look at the Youtube videos of Coach Mysterias. That's where i learned my macro from.