Is it better to reduce drag or increase lift?
Your lift will be prescribed and cannot be freely chosen. So what you need to do is to minimize the drag that goes with this given lift.
In straight flight lift needs to equal weight. In turns, the centripetal force is added to this. At high speed a small angle of attack will produce that lift while at low speed the angle of attack needs to be high. In most cases, takeoff and landing requirements will determine minimum wing size and the maximum lift coefficient of the airplane. In order to not drag around massively oversized wings, most airplanes use flaps to have a decent maximum lift coefficient for takeoff and landing while minimizing their wetted surface at high speed in order to keep drag down.