How about adding some counter play to twitch's stealth ganks?
I notice there's no indicator like
or delayed set up like 
just pops up as he pleases with ult.
I notice there's no indicator like
or delayed set up like 
just pops up as he pleases with ult.

Same counterplay for Rengar R, Eve stealth and Pyke stealth.
Control Wards general work pretty good. Also a sweeper is nice to have if you think he could be trying to gank.
deep wards, wards just in tri and river bush dont work, if you are bot blue side he has 3 possible gank routes, from his own blue through river set up a ward near dragon pit, behind your lane using your red side jungle a ward in the bush behind red buff will stop that, or a lane gank, ward in the enemy tri behind tower. red side he has only 3 and a control ward in tri will stop 2 of those paths, the third is coming through river where a ward in pixel brush will spot him.