Replying to [ahmed000]:I am a chinese supplier,and hope my suggestion here could be helpful to you.
Usually if your order is big enough,L/C is the most safe way to pay the factory.If it is small order,then T/T will be suggested.But if you buy from your new supplier,you need know them well first,so maybe you need have somebody to inspect the factory or inspect your order before delivering,then it will be safe for you to gurantee to receive your order after payment.
For the sample,your new supplier usually ask sample fee and sample freight fee from you before your order,because many customers are asking samples every day,but most of them won't have order come,so more and more suppliers won't provide you samples if you won't pay them the sample fee,especailly the sample air freight fee.But they would agree to return such money back to you after your order.