I've found that this profession involves a lot of experimentation, especially at first. We also call it "evaluative therapy." You try something and see what happens and how the kids perform. You get a sense of their strengths and weaknesses. Then you have more information on which to plan your next session. This is one of the most interesting parts of the job for me--to evaluate children and see what they can do.
Another thing that is interesting about this job is that you need to know when _not_ to do something. Giving a child space to struggle is hard but necessary. I have to bite down on the instinct that keeps me from supplying the answer and think of ways to give hints or "cues" to the answer.
I used "Jr. Outburst" as my game of the week for my language impaired kids. It is great for word recall and categorizing. If a child takes turns giving hints, it can also work well for practicing descriptions. The kids seem to enjoy it. It's hard to explain sometimes to outsiders that we are not just "playing" but that these games have therapeutic value. Just as playing a kickball game is good for your muscles, playing a word game is good for your brain.
My next hope is to start using more books in my therapy. I have some great ideas on using basic fairy tales. They are part of our culture, but many of my kids do not know their plots. I want to use Cinderella, The Gingerbread Man, and The Three Little Pigs. The hardest thing is finding a basic version of these stories--I may have to make my own.