Part of what we learn from meditation is being able to let go of our egos, our expectations, our anxieties and just experience existing, just 'being' is hard, though. It takes practice.
Part of just 'being' is refraining from judging. Think about it and you will realize that wherever you are, whatever you are doing, you spend a certain amount of energy assessing your surroundings, whether it's the people, the sounds, the objects or the smells. You're thinking 'that's nice, that's nasty; she looks capable, he's ugly; it's grey, it's blue'. Try just practicing being aware, but without making judgments,
Soften your gaze as you look at objects. Depending on your surroundings you can choose a smell, an object or a sound on which to focus. A smell can be an interesting subject for meditation: easy if you happen to be waiting next to a bakery; hard if you're standing at a bus stop next to a garbage truck.
How to Meditate With The Waiting
1. Breathe, relax your body. Allow your eyes to go out of focus.
2. Start to notice the smells around you - and there will be some, both nice and nasty.
3. Notice the tip of your nose nostrils and beginning to float through your body like vapor. With each breath, inhale the smell until you are full of it. Now you and the smell surrounding you are one and the same.
4. If you start to think 'this is horrible' or 'this is lovely', allow the thought in and then let it drift off again.