Against ashe, Catch Ashe out of position when she goes to ward. You can then look to take Baron or the Dragon while she is dead.

Keep a constant eye on your champion's movements in the mid and late game as Ashe will usually throw out her Ultimate w “recklessly” in attempts to start the fight. Dodge it and then capitalise on the cooldown. 

Be prepared to back away from an objective if Ashe uses her k to scout vision. If your team is spotted, the enemy will try to contest the objective which may lead to your team throwing the game. Against ashe, Catch Ashe out of position when she goes to the theater. Then you can look to take Baron or the Dragon while she's dead. Keep a constant eye on your champion's movements in the middle and end of the game as Ashe will usually throw her Ultimate w --Recklessy- in attempts to start the fight. Dodge it and then capitalize on the cooldown. Be ready to step back from a goal if Ashe uses her k to spot the vision. If your team is spotted, the enemy will try to challenge the goal that can lead to your team launch the game.