Do airline pilots increase thrust when ordered to increase altitude by traffic controllers?
Do airline pilots increase thrust when ordered to increase altitude by traffic controllers


Yes, without increasing thrust the act of ascending would reduce speed.


  Do they simply use flaps


No, flaps are not used to climb. They are used to increase the surface area of the wing in order to allow the aircraft to fly at slower speeds (for example, during approach &amp; landing).


  What is the altitude increase sequence or procedure 


Generally, and put simply, it is increase thrust then raise the nose.


  Do they simply rely on auto pilot and if so does it increase thrust too?


They may well use the autopilot to do it all, but some autopilots do not control the throttle so that would be done manually by the pilot while the autopilot controls the rate of climb.