All you need to do is to set your preferred sorting order before you save the playlist or collection.
This applies to smart playlists and smart collections.
A ‘dumb’ playlist cannot be sorted, unfortunately.
But there is already a feature request for that. So please vote on this, instead of creating a new feature request: Playlist sorting and searching feature request
Regular collections can already be sorted title and release date, as well as be sorted completely manually. https://support.plex.tv/articles/201273953-collections#toc-5
