Contributed by B@rt.
Here are two good tutorials about how you can create reflections with environment mapping:
https://www.rash.f2s.com/tutorials/env/env.htm
and
https://www.blender.nl/showitem.php?id=100
Contributed by Darkavenger.
To make a simple reflection in blender make a PLANE and go to its MATERIAL options (F5) and select CSP and CMIR in the top right corner and select REFL next go to the texture options and select ENV MAP this will open the enviroment map buttons press SPACE BAR go to ADD and select EMPTY place it just under the camera make sure the X AXIS is facing the mirror now in the OB box in the enviroment map buttons type Empty with a capital E! Then add a mesh infront of the mirror and a lamp facing the mirror press Free Data in the ENV MAP window and render (F12) the image it will show six small images (taking pictures from all angles for the mirror) then a large image will appear this should have a mirror plane reflecting whatever object you chose to be reflected! Good Luck!
Darkavenger