As a user, when I'm visiting my Special:Watchlist page it would be good to know about the existence of Special:Preferences#mw-prefsection-watchlist as these settings effect the behaviour of Special:Watchlist.
There are already several links to editing your watchlist from Special:Watchlist but there is no mention of the watchlist configuration in Special:Preferences which effect the behaviour of Special:Watchlist. For example, settings under Advanced Options control what defaults are set on Special:Watchlist and settings under Display options can stop any results from loading on Special:Watchlist at all (although this doesn't appear to be intended behaviour - see T176033).
This deeplink could be added to mw-watchlist-toollinks at the top of the page so instead of displaying:
For username (View relevant changes | View and edit watchlist | Edit raw watchlist | Clear the watchlist)
It might instead display:
For username (View relevant changes | View and edit watchlist | Edit raw watchlist | Clear the watchlist | Edit watchlist preferences)
For the discussion on what caused this enhancement request see: T176033.