The purest form of Government based on sortition is that all members of parliament are chosen by random selection.
Given how entrenched our current system of electoral governance is, its difficult to imagine such radical change occurring any time soon. Similarly, many political commentators and theorists have concerns about such a seismic shift, and do not support the complete removal of political elites from the process of law making.
Compromises proposals are therefore common. Some of the more popular ones are considered here. I rank them in terms of purity, where 10 is the most pure (the closest to pure sortition) and 1 is the least pure (the closest to our current system). All contain at least some element of random selection.
Consultative Citizens Assemblies (2/10)
Citizens Juries / Veto Juries (3/10)
Authoritative Citizens Assemblies (4/10)
Randomly Selected/Sequestored Voters (5/10)
Upper House Assemblies (6/10)
Lower House Lists / Tying Vote Assemblies (7/10)
Split Assemblies (8/10)
Retained Membership Assemblies (9/10)