Do you normally have a CS advantage when landing phase ends?
You always need to ask yourself "what's the next objective that's going to be contested." If dragon is going to be up in less than a minute then you shouldn't be farming top lane. If the enemy team can rush baron then you shouldn't be farming bot lane.
Most of the time in the mid/late game you should be mid as the ADC since pushing a side lane by yourself is very risky. However, you always need to keep and eye on the side lanes and get the lane pushing back in your favor before an objective can be contested.
If you need to clear a side lane and you're worried about your team fighting without you warning ping them and then ping that you're heading to a side lane. If they complain say "play safe, someone needs to clear side lanes."
Don't be afraid to take jungle camps either in the late game if they are on your way. Your priority should be lane cs but you need to be as gold efficient as possible.
Keep in mind that the best way for you to help your team win is to get as much gold as possible. If you keep denying yourself cs because you're worried about missing a team fight then when that team fight occurs you'll be under farmed and won't have a huge impact anyway.