Many collective decision making problems have a combinatorial structure: the agents involved have to decide on multiple issues and their preferences over one issue may depend on the collective choices adopted for several of the others. Voting is an attractive method for making collective decisions, but conducting a multi-issue election is challenging. On the one hand, requiring agents to vote by expressing their preferences over all combinations of issues is computationally infeasible; on the other, decomposing the problem into several elections on smaller sets of issues can lead to paradoxical outcomes. Any pragmatic method for running a multi-issue election will have to balance these two concerns. Here, we identify and analyse the problem of generating an agenda for a given election, specifying which sets of issues should be voted on together in local elections and in what order these local elections should be scheduled.