Do you use just paper, Email drafts or any special apps? And how do you remember where you have noted down some specific thought or idea?
I've tried several apps like Evernote, Trello, Asana or voice Memo apps ... Also I am maintaining like 2-3 ToDo lists on paper troughout my home. But in the end I often loose tasks, or interesting ideas come up again like 2 months later and I cant remember where I already wrote about it.
What Tools do you use?
If someone sends me an e-mail about something that needs doing for work, I hit a keybinding, and a buffer pops up with a TODO item, by default scheduled for today, with a link back to that e-mail (and any selected text added as well). I write a quick headline, then C-c C-c and it's filed under "Misc" in my work org file. Sometimes I hit C-c C-w to immediately file it under some project heading instead (not much harder because of auto-completion). Since it's scheduled in my work org file, it shows up in my work agenda, which I open every morning and whenever I need a task to do. When I'm working on the task, I might write further notes for that task under that heading. It's all plain text, easily greppable, versioned in git.
I have a non-work org file and capture template too. I go through the non-work agenda a bit more rarely than the work one (spending less time on work is on my non-work TODO), but it's a nice way of sending messages to yourself in the future ("* TODO renew passport SCHEDULED: <2027-01-30 +10y>"). And I feel pretty confident in the system, since I've been using it for over ten years …
If I'm not at my computer and I get an idea or something, I'll typically just send myself a very short message over IRC. I find phone-typing a pain, and rarely have the need to look at my agenda on the phone (though I know there are org-mode phone apps should the need arise).