when my lips are really dry i stick to good old vaselline, out of the jar. i put some on before bed, and in the am and it keeps my lips so freakin' hydrated! I have problem lips (dry and flakey) all year round and vaselline does the trick better then anything else!
Be mindful though that Vaseline can cause blackheads and general blocked pores around the lipline, though.
If I get someone in my chair who has bad dry lips, I put some Elizabeth Arden 8 Hour Creme on their lips. By the time I get to their lipstick, their lips are full and moist again.
I second EA 8 hours.
Here in Australia, there is Lucas' paw paw ointment which works a treat as well.
Of course, prevention is better than cure, so drinking plenty of water and moisturising with lip balm etc.. always helps.