Thinking skills

A reasonable starting point for academic 'thinking skills' is Bloom's taxonomy which sets out a hierarchy of how we think and work with information we learn. An updated approach based on Bloom is here if you want to get more analytical about thinking in educational terms.

Critical thinking links
Monash University

Improving your thinking
There are thousands of ways to improve your ability to think, whether these relate to lifestyle (diet and sleep), approaches and strategies, self-improvement strategies (sometimes called meta-cognitive strategies), etc.

A list of strategies
Mind maps (and there are online tools such as mindmup.com)

Collaboration with others (example online tool https://voicethread.com/about/features/)