So I'll have to put on my thinking cap before writing anything down.
You would know how to best use this energy, so just put your thinking cap on.
He's good at dressing shop windows but he really had to put his thinking cap on when they asked him for an idea for a carnival float.
Scientists in Australia say they are encouraged by initial results of a revolutionary "thinking cap" that aims to promote creativity by passing low levels of electricity through the brain.
