Aim to write "stellar hubs", and keep your fingers crossed.
I heard It helps if your hub gets very high rating and even better if someone recommends it for HOD.
So the trick is writing WOW hubs, with photos, tables, polls, etc.
So try to get as close to 10 as you can on the rating scale (to see it click the link)
I only got one HOD last year, I've been trying to repeat the magic ever since.
Good luck to you! :)