both of those properties are very popular so discounts aren't too common. however, i can offer 2.5 pieces of advice:

1) call the hotels directly and ask to speak with managers

2) latch onto a corporate rate. lots of companies have special rate plans with the st. regis (goldman, mckinsey, and the la times come to mind) so if you know anyone that works for one of those companies, ask them to book a room for you

a 3rd technique would be to book your hotel as part of a package. however, i only know of packages ex-hkg, which probably won't help you much.