Honestly, the only consistent solution for me has been time XD I usually need my brain to chew on it slowly in the background, and eventually a better solution would pop up. So I usually shelf it for the moment and work on another aspect of the story instead (or something else entirely) 
But if I really need a solution now, I'll just go with the subpar solution I do know about; I can always go back and edit it later if I reaaaaally feel the need to
(But really, I just don't put myself in such a position to begin with; I only go with subpar story solutions for reasonably 'standalone' arcs that doesn't need me to uproot the entire rest of the story if I need to change it :P)