Repeat this over a few times. You may not feel much at first, but with practise you will feel a tingling surge of energy like adrenaline and a fluttering or pulsing under your skin as you do this. Even if you don't feel anything you are still raising some energy. When I first started using my chakras, many years ago, I didn't feel anything happening in them for several months. Many people report feeling some sensation in them the first time they do this.
Some people seem to have more natural chakra activity than others.
After any work on opening the chakras it is Very Important to close them unless you are going to use them, or go to sleep shortly after. During sleep they will close naturally after an hour or so. This closing is especially important if you feel strong activity in them. If you leave a chakra open during normal day to day activity, you can bleed energy. This will can fatigue and health problems.