sha jia means haggle, or bargain lor
Of course if your shoppin at those shoppin centres, that will be
fixed price.... so i think TS is referring to those places that
allow you to haggle, like bugis street, fep, or bangkok all these
etc
Technic huh.... hmm....
Product: $300
- Dont appear to be too interested in the product in the beginning.
They see you too gian, then might not cut some prices since you
gian until ready to pay for it
- Once you see somethin you like, set a price that prepares you to
start haggling ($250) 
- Dont haggle immediately. Cannot walk in then start haggling

At least try first ma if it's clothes
- Now starts to be interested for a bit. You offer your price to
the person, see if shes ok or not. Tone used is impt. Dont appear
to be too desperate, but at the same time give her the feeling that
if your given a good price you will buy, your a potential
customer
- If she sets another price ($280), then you minus an amount from
the price she sets ($270)
- If she says cannot, say a few more words to make her change her
mind. If cannot, then use the price she sets ($280) (that is if
your ok with it)
- If she says it's a deal, then good lor ($270)
No step by step technic, depends on situation.
What price should you start with? Depends on where your shoppin at.
Bangkok, China, starts with 1/3 of the price first 
Or you can buy more items and ask for lower prices.
Depends on the product your buying, then maybe point out some bad
points. Sometimes they will auto lower price for you. If some shops
are sellin the same product, then roughly the prices are the same
and fixed but you may buy more and ask for lower prices....
I dont really use this: Another shop has a better price