Best way to go from Yangshuo to Dazhai.

I remember that there are direct buses to Dazhai, which depart at 9:00, and 13:30.

Or, you may take a long-distance bus to Guilin from North Bus Station for CNY 22. The buses are available from 6:45 to 20:30, and the duration is about 1.5 hours. Then, take a bus to Dazhai from General Bus Station for about CNY 40. The buses depart at 8:00, 8:30, 9:30, 13:00, and 15:00.

It is a reply to David : Thank you for your information. It will be very useful for our next trip April 2016.
When was this information valid ? Which yearwhich month ? Thanks as I now know it ispossible to get there easilyone way or another.

The direct bus has stopped running. If use public bus, you need to go back to Guilin and then head for Dazhai. This is the info of August, 2015.
Actually, there are direct buses between Yangshuo and Dazhai operated by a local travel agency. The bus departs every day at 13:30 from Huijingge Hotel (No.1, Kangzhan Road). But it requires advanced booking at least one day before. So once upon arrival at Yangshuo, ask your hotel staff to book for you. The fare is CNY 80 per person and duration is about 4 hours. This info is brand new as of the time of writting.