Ideas - See My Information Management Software page, as these can go into Evernote or Workflowy "depending" on the nature of the items. Evernote is for storing clippings and brief notes for myself.
[UsedI have a "category" in my Achieve Planner (nonsyncable) old time management software (it is "collapsible" so I open it only when needed). I put them into subgroups, by subject or project, when I am into it. This is currrently a sinkhole, unless I tickle them up. ]
Information for reference
All information, little writeups and stuff I am going to work on, hopefully, someday are filed by category and then subgroups, though the subgroups are different than the ideas section.
My Journal (DavidRM) software; Excellent tree outline so it is absolutely referenceable. , Nonsync, on my PC. See special journaling structure: "Working Journal Structure Outline"
"Pages" (word) program in IPad: By overall subject area, then by document subject.
Files working on for writing etc. - in my rolling file next to my desk For longer writings.
"Notes" in iDevices: For simple lists or tell Siri I want to dictate in notes, and then I will access the notes in order. Much of this could be in Workflowy, too - but this is simple, and not hierarchical, but handy.
Email (and contacts) - Using Yahoo now, but gradually shitf to GMail (or send "to dos" for transfering to tasks).
Filing, reference systems, locations - All defined, with structures for each item, category, etc., for retrievability. (in process)