In my opinion giving verbal instructions for graphing calculators is asking for trouble. Oh sure, we all have to do it sometimes. But particularly when the complexity of the process increases it is worth it to have written instructions and/or slides of the process. Your students will thank you. OK, they won't thank you. But they sure will grumble about other teachers who don't provide them with more than just press-this-button-cursor-to-that-menu.
This PowerPoint presentation describes the process of modeling data with a TI-84+ SE graphing calculator and a handout that shows a summary flowchart of the process.