How to make yourself lay down strong hands when facing big bets?

[Steve Chase]

I in general play very well in NL Holdem games.
There is one problem or bad habbit I cannot get rid of.
When I have a strong hand (such as two pairs, a set, straigh, flush, ...etc), I have trouble to lay it down when faced big bet.

For example, when pot is $5
I have two pairs, someone bet $30 into me.
or
I have a straight, flush on board, someone bet $30 into me.
or
I have a flush, pair on board, someone bet $30 into me.

I tend to call in these situations.

For these tough decisions, 80% turns out to be bad calls
for me.

What do you do to get youself laydown a strong hand?
What do you read from opponents to see if you should call?

I used to blame my hand is too close to my mouse.
I click on call too fast.
Now I move my hand far away from the mouse so I can do some thingking before I call. I really don't know what to look to help me making my decision.

Thanks