Take the Mass Rapid Transit (MRT) to Chinatown. Alternatively, you can take the bus or a taxicab to the Chinatown MRT station.
Plan on spending at least two hours. Browse around to see what you feel would make appropriate gifts or souvenirs for your friends and relatives.
Browse all the stalls, noting the prices that are offered for similar items.
Explore the larger air conditioned shops as well. Sometimes, they have just as good a deal as the vendors on the street.
Decide what you want and note which stalls have the lowest price. Circle back to one of your selected vendors.
Ask the vendor how much for the item or items you want even if the price is displayed. Make a counter offer or ask for a price match on the items you saw at another store, and they will usually oblige. This is key: don't hesitiate to play one vendor against another. They expect to haggle.
Ask the vendor to give you a discount if you buy more items from his or her stall.
Walk away from the store if you don't get a reasonable price for the item you want, as there are others that carry the same merchandise. The vendor will typically make you a counter offer or accept your offer when he or she realizes that you are willing to leave.
Have fun.