Of course you must always clear an area before beginning any turn, and look straight down to establish a reference point on the ground and note direction of drift. But then what? Most pilots have an unconscious habit of looking almost constantly sideways in the direction they are turning. Some have been taught to, presumably to watch for traffic. But the one place you’re least likely to see surprise traffic is inside your circle. Looking mostly straight ahead, on the other hand, will provide a continual scan across the horizon while circling, about twice every minute - and looking straight ahead also helps in maintaining attitude and coordination by reference to the horizon and yaw string.
A common lament of inexperienced soaring pilots is: ”I find what feels like a good thermal and turn, but then it seems to be all sink!” Sometimes that is what happened, but neophytes often turn too gradually and fly around the lift in thermal sink. Unless there’s evidence that the thermal is very wide, it’s better to make your initial turn a tight one, to pinpoint where the lift is and avoid flying away from it. In good lift, a turn that is steeper than necessary doesn’t bring much penalty, but one shallow turn in sink can leave you out of the thermal – or even beneath it.