The design of direct democratic elements, such as popular referendums, varies greatly across democratic constitutions. This chapter enables countries to configure their own constitutional clauses by offering a modular system. Firstly, it addresses the fundamental question to what extent if at all direct democracy is beneficial for each country. It then reviews the many different factors that influence the hurdles and the outcome of direct democratic elements, such as whether they are proactive or reactive, held at the local, state or federal level, whether they are a one- or two-step process, whether they involve parliamentary intervention or other external oversight, and, most importantly, what the turnout and approval quorums are at the different stages of the process. Other factors include the method of signature verification, the determination of the voting day, and the overall timeframe, all of which have a significant impact on the probability of a popular referendum’s success. All these factors must be carefully assessed against the idiosyncrasies of the electorate of each country. Finally, alternative solutions and the implementation of successful ballots are discussed, providing a comprehensive toolbox for the constitutional design of direct democratic elements.