Thanks a lot! I was surprised myself.
And writing it all down got more extensive than I expected. :D

I'll continue now with the other two things.


- This one was a deduction I wasn't planning to make: at a gas station the working shift just changed.

As you already know, I stood there at the tram station quite observant to everything that was happening around me. Suddenly I noticed a very thick guy (he was fat really) walking down the driveway of a gas station directly across the street where I stood waiting. He lit a cigarette before he crossed the street and he had a bag or rucksack with him. I was wondering: Wait a minute, where did he just came from? There is nothing really else across the street except this gas station and nothing else from where you could have gotten onto that driveway. He must have come from inside the gas station. But why?
And then, one minute later, nearly the same thing happend again. I saw a woman standing in the driveway, lighting a cigarette, ready to cross the street (which she did and then was waiting for the tram). She, too, had a bag with her. I was upset, that again I saw someone standing there and I hadn't seen where that person came from. What was going on?? Apparently both were desperate to light a cig, have they been working in the gas station? From all the places where you're not allowed to smoke of course a gas station is among them for a very good reason. And as soon as they where on the driveway in a distance they thought safe, they lit a cigarette. Determined to observe this phenomenon closer I didn't leave the gas station out of my eyes. And indeed, a minute later I saw movement at the glass entrance door. One person was returning to his car at the fuel pump. But one other person, a man, again with a rucksack, was walking towards the same driveway where the other two have been standing before! He didn't have a cig, though. But now i was quite sure of what I was already suspecting. What person can it be, who walks out of a gas station, but not returning to his car and not having anything visible with him that he could have bought inside (no coffe, no snack, no newspaper)? Who is walking to the tram station and has a rucksack with him? And it is around 8:30 p.m.! He and the other two must have been working there and if three finish work at the same time, it was time now for another working shift. Probably the night shift would begin now.
Some things are a bit odd... Why was each person leaving seperately? I don't know... But maybe working at a gas station is a job you only do for a limited time, as a temporary job and you are not that close with your collegues? Three people finishing their working shift at the same time and this gas station was only medium-sized. Three persons seemed a lot to me at first. But maybe it was one cashier and one working in the background? Then there is only one person left. Maybe a cleaning job or even two cashiers? Then you have a job for everyone of them.


- a young woman, her outward apperance is important to her and she is meeting up with friends to have a nice evening.

This woman was a bit of a question mark to me. :D I had a hard time to deduce something and she was the one where I was the most uncertain, if i got anything right about her.
She was already sitting in the tram when I entered. She was a young woman (~20) and was wearing lots of make-up. On her eyes, lips, face. Her eyebrowes were trimmed. Her hair could have been artifically smoothed out. She had a black handbag with her. (One of those ugly, kitschy ones, that are not my taste ) She was having long and painted fingernails, was wearing a young fashioned black leather jacket, tight jeans, low socks, so that a good part of her ankles was bare. She was relaxed and sat sloped on her seat against the window and had her headphones in her ears. Where was she coming from? Where was she going? Going home? To work? Meeting friends? Having a date? 
With those bare ankles and not so warm jacket I would be shivering with cold after more than 30minutes outside. I suppose she was heading for an inside location, whatever it was. This and her appearnece eliminates any work outside. What other work could she be going to at this time, 8:30 p.m.? With these fingernails, nowhere in the health sector and not cleaning up somewhere! A waitress in a bar or restaurant? It was Wednesday evening, I believe all bars would be closing at the latest around midnight. If that was her job, she would surely start earlier in the evening. In a hotel lobby? Well maybe... but we have only few hotels in the town where I live (not Frankfurt). Well, for a real job, she was too young, anyway, I think. She was probably still on training for a job or a student. All circumstances make heading for work unlikely and meeting someone much more likely. But isn't it possible that she was coming from somewhere and going home? I don't think so. She left the tram and was walking away at a station with lots of shops, Cafes, Restaurants, bureau and administration buildings (most of them closed at 8:30 p.m.) with barely any apartments around. So again, back to "meeting someone". Maybe she had a date, but if it was, it wasn't a first date, I'm quite sure. A person caring so much about her appearance and putting so much effort in it would surely do a last check up of her hair/make up to see if everything still looks fine before meeting her date. And I think one would behave differently. For example checking the time, sitting more upright, being a tiny bit nervous. But she was totally relaxed and she didn't do anything else than listening to music with headphones the whole time.
So I suppose she was meeting with a friend/friends to have a nice evening at a bar/cafe/club.


That's it. In all four cases I described things could still be very different. I had lots of other ideas, but those were the most probable ones, don't you think? No idea why i was so observant and creative and had so many things crossing my mind. I haven't tried this often (10? 15 times?). I think you need some luck to make some good deductions. In this case I was lucky with the circumstances. The time and the weather for example. Some deductions wouldn't have been possible otherwise.