Cheap Flights Holidays

Hi,
I’m looking for details on cheap flights from London to Hong Kong.

I’m not talking about Oasis - I already know about them.

What I really want to know is:

1) what time of year is best to go?
2) which carriers do cheap deals and when? I seem to recall that Cathay Pacific and BA do some cheap deals every year.

PS please I’m not interested in big booking engines like expedia - these do not capture the deals that I am looking for.

Thanks

i want to go on holiday in October and I want to find a cheap return flight to Hong kong but I still would like to know if anyone knows of any really good discount ticket sites etc.