Sit comfortably, place your hands in front of you a couple of inches apart and close your eyes in front of you a couple of inches apart. Direct your energy into your hands and then into the space between. Push it back and fourth from one hand to the other. If it helps, give it the shape of a ball. If you can work with someone else play 'catch' with it, gently pushing it from one person to the other.
Learn the 'personalities' of some objects, a stone, an old watch, your grandmother's quilt. What do you fell when you hold it? Are there any images that come into your mind? You must keep both your mind and heart open, don't dismiss thoughts that you may feel are silly.
So you don't drain yourself every time you work you must learn to draw up the energy of the things around you. One of the best and easiest is the earth itself. Like when grounding, you want to pull the energy up.
Please remember to return energy that you don't use or need, holding onto it may cause you problems.
Unfortunately, you can't teach someone how to feel the energies in the world around us. Some may never be able to but the more you try to open yourself up to it the better you will become.
Image from the NY Reiki Center