Cant make forhand serve during tournament

Recently I play in a local tournament. My usual weapon of forehand serve and then attack failed miserably. Reason being I was somehow unable to serve using forehand. It's kind of weird as I just dont have the feel when I serve and thus all my supposingly spinny serve become just like no-spin serve.

From my frens' advice and my own analysis, it was due to following:-

1) Focus too much on serving esp on my wrist. Thus somehow it wasnt working anymore.

2) My fren told me that it was not my hand that gave me problem. More of my waist was not turning and thus the coordination btw my wrist and waist all go haywire.

3) Nervousness as I kept wanted to serve better. Muscle then became tight.

Anyone who have such experience before? What is your advice? Thank you.

I would like to offer a couple of observations.  First, as your serves become more advanced, esp in terms of short height barely clearing the net but also with spins and short/long placement, they become more sensitive to changes in conditions.  When you were serving an inch above the net it didn't really matter so much. 

Second, what kind of table are you practicing on versus tournament play.  At home my cheap table is fast and not very grippy.  Then when I get to a tournament and a nice table I have to make a big adjustment.  My backspins grab a lot more and tend to sit up or even fall short.  So I try to serve an occasional very tight serve when I "feel it" and the rest of the time I'll settle with a safe height and length.

I once had that, I served and the ball either went to long or to high....

I found all I had to do was loosen up, think about the spin on the ball, dont think about the service action.

Play practice points during your tournament warm-up or even short practice games. This will help you duplicate match conditions and will force you to practise your best service at the tournament venue.

Also, remember not to rush your serve. Some players hurry through their service and end up serving without the right body balance. The resulting body balance shifts throws off the serve. Lastly, remember you don't have to clobber the ball to get big spin.

Good luck in 2007