The most effective early aggro play for CTs on B is to take short/sewer control and put pressure on connector. This molotov either forces Ts to wait and give up the angles to the CTs or use a smoke to extinguish the molly and take a disadvantageous fight.
Difficulty: 2/5
Importance: 4/5
Stop anywhere as you exit the area under heaven into ABC, the exact position does not matter very much but here is an illustrative example:
Find the corner of the third balcony visible from the bottom and do a standing left click throw:
Result: