Hey!
In this little tutorial I want to demonstrate you, how I achieved a reflecting surface effect - in this case a puddle.
This is a scene I made and people asked how the reflection is working: https://cospac.es/edu/I1oa
I started with building a road with some cubes and added another cube with low opacity to represent the puddle.
The actual trick to make it look like a reflection is to have the same scene underneath the surface as seen here:
This is the the little demo scene I made for this tutorial where you can easily see what is going on: https://cospac.es/edu/kjcU
Have fun!