As modeling languages become increasingly sophisticated, the reusability of individual language components and their integration into full-fledged languages is essential in language engineering. While different composition techniques have been established over the past years, language engineering endeavors still too often start from scratch instead. One reason is that although these techniques, such as extension, embedding, or aggregation, are elaborated and studied, they are rarely used in practice outside of research. This tutorial aims to bridge this gap by providing a practical course in which heterogeneous languages are developed and further integrated via advanced composition techniques. Using the MontiCore language workbench, we demonstrate hands-on the benefits of reusability in language development such that the advantages are already experienceable in a single session. The tutorial starts with a short introduction about language composition techniques with their respective fields of application and then proceeds to the practical part, where participants develop modeling languages themselves, combine them, and use the integrated result.