如何練反手..

如何練反手..還有,發球有甚麼翹門?
反手 - 分雙手及單手兩種
反手 - 90%球員覺得較正手難打
其實反手的手部動作球球都一樣的(俏, 平 或topspin), 主要看你雙腳能否踏正適當的位罝. 掂波必需在腳尖前, 此舉你可選擇抽打直或對角, 否則你只會被波揰版而非版打波.
盡量在來球彈得最高(點)時打(hit on the rise), 可借力時又可由高打下. 美國名將阿加斯(Agassi)是打這欸球的表表者(雙手反手), 對手根本捉不準他是抽直或對角, 可惜他己退休.

發球 - 第一發球要求是高球速
右手球員 - 左腳在前, 右腳在後約一呎, 左手拋波頭頂前(不要擲), 打波時腳部重心由右腳轉至左腳, 拍在左腳腳邊經過完成.
有甚麼翹門?
1./ 拋波一定要在頭頂左眼前半呎, 高度是右手舉盡的拍頂位, 這時的波最輕.
2./ 轉重心時腰部要配合, 否則難以發力.
3./ 打波時(impact)一刻要用手碗力壓下去才能產生高速. (手碗- 在網球多種動作中均需鎖緊, 除了發球和高壓球時)
希望能幫到你反手和發球進步!

the above answer is good
just want to add one personal view...

although we can turn our wrist during serve and overhead, i don't suggest using the wrist as power drive. Maybe we should let it loose, (not locking the wrist, as in other tennis strokes) but not to rely too much on wrist to provide power.
2 reasons:
one, it won't provide too much power. the main power comes from the thighs (jump up) and the waist 腰 turn (to attain a fast racket head speed).
two, if u mis-hit (esp at the tip of the frame), u can easily hurt the inner forearm muscle and even cause a golf elbow injury. one way to avoid this injury during serve is NOT to hold the racket too tight during serve. Relax the whole body before serving is a good way to practise reliable serves.

JUST Personal views

and pls find a tennis book (English version) in public library if u want some comprehensive knowledge in tennis. Much better than $3000 coach fee can give U.