The rules for designing wards are set out in the law, and include:

• the aim to produce wards where the electorate for each councillor is as close to the average as practical,
• the need to fix boundaries which are and will remain easily identifiable, 
• consideration of any local ties which would be broken by fixing any particular boundary, and
• following the introduction of the Scottish Elections (Reform) Act 2020 each ward can elect between 2 and 5 councillors. The Islands (Scotland) Act 2018 additionally allows 1-member wards within those 6 council areas covered by the Act, where those wards contain inhabited islands.