I offload tasks until the student can cope with the workload. As his/her capability increases I add back those tasks I was doing for them.
If they need a wider circuit initially then fine, use a wider circuit to give a bit of extra thinking time. Sometimes I'll re-demo the circuit to keep in their mind a 'model' circuit.
A satisfactory ability to climb, turn, level off & descend are prerequisites to commencing circuits.
If a student is really struggling with those skills I'll return to the training area for additional practice. If the circuit is OK but the landing is their major trouble point then I'll modify the circuit, if possible, to increase the number landings per circuit - even if I have to fly the a/c to set up final.
Examples of this can be in a 90 deg. crossed runways configuration + calm wind conditions allowing a 'clover leaf' circuit, shortening the circuit time per landing. Other ways include tear drop circuits to give landings in alternate directions. Again, calm conditions etc are necessary.