Indenting width in Xcode, by default, is defined as four spaces, and tab width is also defined as four spaces. We should leave this as the default. The following screenshot shows the indentation setting in Xcode:
We should add an extra blank line between functions/methods. We should also use a blank line to separate functionality within a function or method. That being said, using many blank lines within a function or method might signify that we should break the function into multiple functions.