Just a couple of tips towards this trophy:
For the materia pickup, it has to be done in under 14 secs to get the +5 affection. You will also get the godlike trophy doing this.
For the perfume blending you have to do it correct 3 times to get the full affection from this. You will also get the master blender trophy for doing it correct once.
The affection points are gained from:
1. +10 from each store owner when looking for Bruno. +30 in total.
2. +10 from both the boy you give potions to 5 times and the girl where you wait 10 times. +20 total.
3. +10 for selecting you'll buy the medicine for Bruno.
4. +5 from the materia pickup mini game.
5. +5 for each correct perfume blend. +15 total
You should have +75 affection after all that which will get you the trophy after speaking to Bruni when leaving the area for Shinra. He should say that you and Aerith make a good couple, that's when you know you've done it right.
Hope this helps. Any questions please ask.
