The first examples of non-arithmetic complex hyperbolic lattices were constructed by Mostow in 1980. These examples are generalized triangle groups generated by complex reflections of orders 3, 4 or 5. We will see how to parametrize such triangle groups and how to identify which of them are lattices. We will then survey an ongoing project with Deraux and Parker whose goal is to use this idea to construct (many) new non-arithmetic lattices in SU(2,1).