For a best practice in creating predictive models in R, look at the caret package website. Caret is short for Classification And REgression Training). Note, this is not intended to cover all of data mining (such as clustering, association rules, optimization, NLP), just forecasting or prediction.
The support is to provide a unified, consistent interface over all the algorithms. For example, the model formula between dependent variable and independent variables is mostly consistently followed, but not always. Caret covers