Experimental design is a desirable outcome of laboratory education. Incorporating inquiry into the laboratory curriculum is attractive, but there are acknowledged concerns from practical, theoretical, and epistemological perspectives, and these are accentuated in upper-division courses. In this work, we draw on the extensive literature relating to experimental design and inquiry learning to conceive a pragmatic laboratory curriculum that invokes the development of experimental design skills in a structured way. The model also incorporates the core principles of formative assessment, so that students get a chance to improve their work on the basis of feedback as they are doing it. We illustrate this model with two examples from our own practice of upper-division physical chemistry, but the basis of the design is elaborated so that interested readers can adopt it for any aspect of practical chemistry where there is a desire to incorporate experimental design skills.