Dont be afraid to use your spells, use always your Q, if you dont have range to an enemy, use it to minions to stack your tornado...Also use your E and try to dodge enemies spells and to escape/move fast, and mainly use your W, if you see that you cant dodge some spell, just use W and block it :) Yasuo doesnt have big cooldowns, dont be afraid!
Lets learn some combos!
1. Beyblade: You need to stack tornado and then you do E,Q to minion and immidietly flash to the target!
*You cant be so far from champion.....So you have tornado active, you do to a champion and you will knock up him and can do !
2. Airblade: You need to have tornado active again and you also cant be so far from target...You need to throw the tornado on a champion, knock up him but before you ult him, you need to fast do a E,Q on him and then ult. So you throw then you and then !
3. Keyblade: Thats combination of last to combos, so its Beyblade + Airblade...Its hard but you can do it! You need to have tornado active and you do E,Q on minion, flash to enemy, do E,Q on enemy and R!
Lets use some pictures now, you have tornado, you do then on minion and to an enemy, then on enemy and !
4. In some cases you can use little help called InstaDash, that means that you ult somebody and immidietly after your ult you dodge with E...You know, somebody waits while your R ends and straight use his R and you can dodge it like this.
It will be hard at the start so use Practice Tool and try it there but I believe you, after 3 days you got it! :)