The Further Mathematics Support Programme (FMSP) produced a range of problem-solving materials for post-16 students, including materials created for a Year 12 Problem Solving Summer School. These resources are available within the FMSP Resources Archive.
Materials from past Senior Team Maths Challenges (STMC) are also a good source of problem solving practice.
As part of the support MEI provides for STEP, it also provides access to sample materials and access to past paper worked solutions.
Further materials for introducing and developing these skills are available from: