The growing usage of tokens in real-world blockchain projects – mostly visible in ICOs – has unveiled the need to understand what blockchain tokens in fact represent and how they relate to their underlying business model. Previous research has contributed to this gap but often lacks a comprehensive understanding of tokens and their design as well as of the growing and rapidly-changing complexity in token landscape. This has crucial implications for assessing tokens' value and utility. Applying a structured, scientific approach towards blockchain tokens, we provide a comprehensive token classification and a decision-aid on token design. This is based on a literature review and an empirical study to cover this research gap. Our work offers a novel contribution in an emerging field within the Blockchain research domain and proposes structured analytical tools which can be used by both practitioners and researchers.