On the 787 we set a master cabin temperature in the flight deck between 18 and 29 degrees. The cabin crew then have the ability to adjust this temperature by +/- 3 degrees, within the above ranges. The air conditioning system maintains this temperature through all phases of flight.

I usually set it to 21 and then the crew can adjust accordingly. To my knowledge there is no guidance about what temperature should be set in the cabin, but I stand to be corrected.

EDIT: Guidelines for cabin temperature are 22-23 on a day flight and 21-22 on a night flight.