Hi there,
I want to share my 3 main tips for staying calm with your todos...

__First Tip - The SANE.INBOX__
Derived from the principle of "Do it Tomorrow" by Mark Forster (markforster.net; author of highly recommended books) and my experience to always got seduced to look the hole day again and again in the inbox, I introduced a smartlist called "MyInbox" with the following search:

"addedBefore:today AND list:Inbox"

So, I see tasks coming in today only tomorrow.
Sameday urgent items got "priority 1" or "due Today" or got "starred" (see below) so they will show up in the Today list or in a corresponding smart lists.

__Second Tip - The PIN__
The PIN is a tag which is part of every smart list. So, when I temporarily "pin" a task it will be shown in every smart list and can be easily accessed. If the task is no longer needed, the pin got removed.

E.g. "(your smart list) OR tag:pin"

__Third Tip - The STAR__
I love the star at wunderlist (God save WL). So I introduce a tag "X" (looks nice with an emoji e.g. "x:star:").
Because I only assign dates if really, really required (to stay sane ;-) I build my lists context related (home, hive, out, ...). After processing my inbox and bravely access my today section I look in my appropriate context list. I work through this list and "star" items which I "want to do in the next hour" (sometimes I change this depending on time available and mainly according to my mood).
Smartlist: ":star: STARRED"
Search: "tag:x" (simple as that ;-)

I hope that this simple tweaks could reduce your blood preasure and keeps you sane...

Best wishes,
Jens