Like in any breakfall it all about following with your center long long before actually fliping over.
E.g. in shihonage, there are basically two variations of sutemi.
1. Nage keeps the hand (ukes) close to the shoulder (ukes) and throws. Uke relaxes and follows with the upper body as long as possible before going around.
2. Nage lets out the hand from the shoulder allowing uke to take the breakfall as in say kotegaishi.
In both cases it about following as long as it is possible so that your center of gravity is as high as possible over the point of control (elbow/shoulder in #1, wrist/elbow in #2).