I also really like that we use the EnVision math curriculum. It is easy to use, has a great lesson set up, and plenty of support materials. I think the units are systematic and sequential. I also like that they encourage you to incorporate math literature.
Another aspect of my math instruction that has been successful was implementing a rotation of Daily Math during my Daily 5 rotations. I started in January when I realized that my students were not getting as much hands on practice as I thought they needed. I have been making games for the students to practice their skills. Here's one of their favorites!