If you want to cross-wires (no join), the convention is to simply do that.
Where you can help avoid later poor-reproduction confusion, is to also apply the rule that non-crossing(joined) wire never form a ‘+’ , but instead join as 2 ‘T’, (all with tiedots)
Of course, these days analog scanners / copiers / faxes and folded printed copies of SCH, are not common,
but such convention can still make fast-visual-scan of a drawing easier.
It is a convention in the industry, one that is adopted by some companies and some individuals, but it is far from being a standard convention. Just looking at some reference designs from TI shows both conventions being used depending on the engineer that drew the schematic. Same goes for reference designs from Maxim. In both cases the convention of no connected ‘+’ wires is not enforced by the company but rather a personal preference of individual engineers.
With a schematic capture tool that properly enforces the use of junction/connection dots it becomes a non issue in any case. Unfortunately KiCad does not enforce the use of junction dots.
Edit: In my opinion, many schematics that avoid connected crossing wires look cluttered and sometimes confusing.