Sentient artefacts are everyday objects augmented with digital services. Being the building blocks of our surroundings, these artefacts can incrementally integrate computing into environment and can convert it into an intelligent one economically. In this paper, we report our experiences with sentient artefacts to rationalize intelligent environment. We discuss the design principles of sentient artefacts and present a sensor selection framework to convert a regular artefact into a sentient one. In addition, we discuss the application development guideline and lessons that we have learnt through prototyping sentient artefacts and proactive applications.