For me.. I recently found new info for one of mine, I started a new PRIVATE tree on Ancestry and entered the few bits I had, using the best estimate dates I could!
From there, I clicked on the leaf in the centre of someone's profile page and Ancestry FED me the best hints!
In fact it was nearly too easy! For one person the hints were incredible it would be impossible NOT to find him!! I did an Ancestry Search and got over 30,000 Hint returns... I clicked the leaf and got 5 VERY relevant HINTS.
By starting with a new PRIVATE tree it meant I could put new data in without messing up my own tree and then add them to my actual tree when I knew they were actually mine!!