Laning-wise, it's a question of whether the enemy needs the cs more than you do. If they're struggling to farm already, there's no point in putting additional pressure unless they're incredibly item dependent and required to do well for their team to do well (Orianna might be an example of this). And even then, it might be too much risk of overplaying and giving them kill gold and a free lane for half a minute.
If you're a farm dependent champion like Jax or Vayne, then farm all day and wait for your jungler to be aggressive. You can still put the occasional bit of poke down, as you should just to keep them on their toes and keep the laning tempo in your favor (tempo meaning you decide when anything happens (if you walk forward and they walk back, then you probably control the tempo)).
If they're farming easily while you've put no pressure on them, you probably need to put a little more pressure, at least during the cannon wave, to hopefully deny them their cannon minion or make them pay dearly for going for it.