We have found a method to review kriah rules in the older grades that is bekovedik and has built in motivation. Every class says a perek of Tehillim every day after recess with each girl reading one passuk aloud as the others say it quietly. The teacher then says the yehi ratzon for a list of cholim. We found that in every class a number of girls were butchering many of the words.
      What we are doing now is the following. Before starting the perek the teacher pulls out 2-5 words that are difficult for any number of reasons, writes them on the board and analyzes the difficulties with the girls. If it is a particularly difficult word she will give out highlighter sticky notes, (we get them in the dollar store here,) to put over that word to remind them to focus carefully when they say that word. Each teacher gears the words she pulls out to the kriah issues that her class seems to be having. Tehillim is ideal for this because we preface this program by going trough the tefillah said before and after amiras Tehillim that invokes the zchus of the words, the letters, the nekudos, etc. So that if we say Tehillim accurately it is much more powerful. (Part of the teillah also speaks about the taamim, perhaps this could be nogaya to boys classes.) Also Tehillim has many, many unusual formations that sometimes clearly illustrate some kriah rules as well as break some kriah/dikduk rules. We have found that the girls are fascinated.
      We are in the process of creating a Sefer Tehillim with all unusual rules or exceptions highlighted to make it easier for the teacher to plan which words she will pull out, depending on which rules she is focusing on for her class. So far it is working for us, although we haven't been doing it long enough to see really solid improvements. What we've seen immediately is the ratzon to read more accurately, and we consider even that a major accomplishment.