The concept of desirable difficulties is central to many of the evidence-informed strategies - such as spaced practice, retrieval practice and interleaving - that have become so prevalent in recent years, and so are one of the most crucial building blocks of cognitive science. Based on the finding that instruction and tasks most effective for long-term learning often hamper short-term performance, they are also one of the most counter-intuitive.In their seminal work, Elizabeth and Robert Bjork identified four desirable difficulties - so called because they improve long-term retention and transfer while making learning seem more challenging - including varying the conditions of practice, spacing, interleaving and practice testing.Isaac Moore and Jade Pearce build on this, explaining each strategy in detail including a summary of the research evidence that supports each difficulty, how it might look in the classroom and how it might be implemented with the greatest impact. They also discuss why students often fail to use these strategies in their independent study (despite their effectiveness) and how teachers and school leaders may encourage students to use them more. Succinct summaries and case studies from a range of practitioners will enable all readers to utilise desirable difficulties in their own classrooms and beyond.