My advise to you is try to get your F2L pairs in one motion and look ahead.
I'm confused, when again did he ask for advice? He posted here to show off his sub-20, not to be instructed on how to get faster. If he wanted help he would have asked for it. Nothing is worse when you want to feel good about something, then someone comes along and tries to tell you how to get better.
Thomas: Great job! I remember my first sub-20, so amazing =D Next is the sub-20 average =p