You can have 5 wards on the map at any given time.
3 stealth wards(green wards 
)
1 vision ward(pink ward 
)
1 blue ward(whatever you call the visible ward dropped by the farsight orb trinket 
)
Use this knowledge. Abuse this knowledge until rito makes the blue ward count toward your green ward total. This means that if everyone on your team does this you could have 25 wards on the map. You're welcome.
IcyPepper1 votesimplying that anyone other than the support wards anymore...
It makes me cry when I'm the only one with an upgraded trinket and the map is completely barren of vision.
DrathTurtle3141 votesjunglers ward...sometimes...I think...any lee sin players out there?
IcyPepper1 votesI buy wards as a jungler.
I might be a rare breed ;~;
DrathTurtle3141 votesI buy sightstone as a jungler, on occasion. though more often then not I forget and just buy pocket wards...
IcyPepper1 votesI've been wanting to on champions that scale well with health (and since cinderhulk, buying sightstone doesn't even set you behind anymore!) like Vi or Volibear.
Then ward top lane.
And counterjungle until kingdom come.