I often have to do the same task and sub-tasks but they are not on regular intervals. So it would be nice to store a favorite or repeated task as a template.
I guess until you make it a built in option I could create a folder called templates and build my task and then copy and paste into a "live" area. The negative would be setting task completion goals because i would have to edit each task and subtask for a completion date. If a template it could be like +5 days from creation, etc.
But I think ticket templates would be great and in some cases might be shareable to the Wunderlist community.
It would help with the tediousness of having to manually re-create subtasks, or manually create tasks with subtasks for all scenarios, find them, copy them, put them in the right spot when a simple select from template option would be much quicker and easier.
https://wunderlist.uservoice.com/forums/136230-wunderlist-feature-requests/suggestions/2315889-template-list-or-duplicate-lists-also-known-as-co (Highly voted up, includes Template Suggestions for Lists).
https://wunderlist.uservoice.com/forums/136230-wunderlist-feature-requests/suggestions/10403478-export-task-list-like-a-template-that-other-users (While it mentions 'Other Users Can Import', as long as I can import it and have the option to share or not share publicly, that works too).