Gassho means two hands coming together. Gassho should be practised twice a day after getting up and before sleep, for maybe around 20 or 30 minutes.
Sit down and make yourself comfortable, spine straight. Close your eyes.
Perform Gassho and concentrate on your two middle fingers. As thoughts come into your mind, as they surely will, just let them go and return to where your two middle fingers meet. Try to forget everything else. That's it!! simple. Now try it for yourselves.