What's the best way to increase your chances of successfully booking a business class ticket on Cathay using Miles?

If you have a fixed itinerary, it would be better not to risk it on the waitlist.

Keep searching for award space and don't give up. CX likes to release award seats 1- 2 weeks before flight

Since you Have a fixed itinerary there are very limited amount of options you have.

have you tried calling their agents for help?

Hi anon,

Sorry to hear about your situation. I don't have experience booking Asia Miles at the emoment, but if you are slightly flexible with the itinerary, then flying in and out on a weekday other than Monday and Friday will greatly increase your chances of a seat, since plenty of business travellers will travel on those days, and on weekends as well.

Short of Cathay, consider using Asia Miles and route through other places via other OneWorld airlines. Unless it is the Cathay business class you specifically want to experience.

Use expertflyer to check the occupancy of the flight. If business is quite full even this far out, then chances are, your waitlist won't clear, and you will be better off buying economy and redeeming next time.