my answer is three practice, practice and practice

this is good practice for players who is not sure how to use the wrist

the players using shoulder to smash instead of writst

remember the main power 80-90% of power in smash

is created by wrist, not arm, not shoulder

so the wrist has to be used, to feel it

this is empty badminton box, make like that

sit down in the chair, so nothing else has to be used.

you have to use only wrist. ok set, left foot here right here like that

come in front, so ready set

not

not arm

it is wrist

if you have a mirror, its better to face mirror

if you don't have a mirror, use a window

so that you can see yourself

so lets practice, set

one - set smash

two

three

four

twenty

rest, relax

and then set one, like this

what you have to do is really smash ready

you have to imagine shuttle been hit

set shuttle come left bang ready, do that twenty

ten sets every day

one two three four five six, two - one two three four five six, three...

do twenty, 10 sets

ok watch this, James come practice

one

two

three

four

five

ten

ok

ok now, you can do this way 10 stand still

set 10, ready go

one

you cant

two

three

four

now attack, ten

ok, so he did stand still hit, to know timing and power

and you move with step to learn training steps that's one set

and you can do 10 sets

you can do 10 and 10 one set

or you can do 15 and 15 one set

if you are really stronger you can do 20 and 20 one set

and usually train about 10 set

ok lets do second set, stand still go

one

two

watch it higher

three

more wrists -four- bang yup

five

ten

ok now set, you say 1, its better to call himself 1, it means opponent hit

then you make steps

one

two

stop

as he did, with this practice you must do one and then

remember to do the loading step

one

two

ten, ten

now, you can use cover, ok now ready

feed it please, with racket

set one

two

three

four

five

you can use racket cover

or you can use heavy racket, you can buy

heavy racket for badminton in any badminton shops

two three times heavier than normal racket

ok, go 2 3 4 5 6

1 2 3 4 5 6

1 2 3 4 5 6

1 2 3 4 5 6

1 2 3 4 5 6

well done