Start your exhale before you start making any sounds. The G sound requires your tongue to kind of come up and back (sort of.) Hit that G sound so soft it almost isn't there. You're almost going to say "ood Evening" with how soft the G sound is going to be. Exhale through the whole phrase. Like I said, that G should be soft. Feel how your G sound normally feels in your mouth. Tongue up between your top back teeth. Try the G sound without feeling the tongue touching there. Watch your lower jaw for tensing.