As International Investment Agreements (IIAs) continue to evolve and become increasingly complex, a key challenge for developing countries is how to maintain coherent investment obligations that are consistent across any overlapping treaty provisions. An even greater challenge is the effective negotiation of trade in services and investment commitments in Preferential Trade Agreements to make foreign investment supportive of development. This guide is designed to assist developing countries to negotiate IIAs that are more effective in promoting their sustainable development. It identifies and consolidates emerging best practices from existing treaty models, evaluating the costs and benefits of different approaches; suggesting new and innovative provisions to encourage foreign investment flows; and outlining how states can achieve coherence among their IIAs.