Please feel free to reply with more situations and/or more opportunities to these situations. We can open a discussion and I'll add them on here.
Situation #1:
You have placed a counter ward and you're aware of where the enemy ward is. The enemy ward oversees some of the neutral camps.
Opportunity:
If you have a tank that can survive 5 on 1 pounce for a few seconds, bait the enemy by leaving him to farm alone and situate your team just outside of the ward vision to intervene.
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Situation #2:
You have genocided them. But when you push all the way to their base but they've all respawned, so you can't push further. Your team is relatively full hp and mana.
Opportunity:
Assumptions: Top or Bot lane, Enemy does not have game changing skill off cd, Night Time
Just in front of their base is a valley. Retreat uphill and wait for them to use some of their low cd nukes/stuns on creeps (e.g. Hammer's stun, Vj's stun). Jump on them as soon as they do to get a second genocide.