A panel of experts reviewed dozens of studies and identified five (5) recommendations for improving fraction instruction. From page 1 of the document:

- Build on students’ informal understanding of sharing and proportionality to develop initial fraction concepts.
- Help students recognize that fractions are numbers and that they expand the number system beyond whole numbers. Use number lines as a central representational tool in teaching this and other fraction concepts from the early grades onward.
- Help students understand why procedures for computations with fractions make sense.
- Develop students’ conceptual understanding of strategies for solving ratio, rate, and proportion problems before exposing them to cross-multiplication as a procedure to use to solve such problems.
- Professional development programs should place a high priority on improving teachers’ understanding of fractions and of how to teach them.

This list fits well with the approaches I've found successful in my own classroom (previously) and in the experiences of my credential students in their classrooms. Learning to make sense of fraction concepts requires deliberate activities that allow for sense-making to occur.

Some resources to help you design such learning activities are:

Have fun with these! It is always great to see students "get it" when working with fractions.