When given the opportunity to meet with sellers, ask them why they are selling. The reasons could be anything from job change to a new location to financial problems. If you can solve their problem, whether it is cash related or time related, do so. For example, if the sellers are highly motivated because they need to move quickly, give them a fast sale - and a lower price. If you can make an offer, even a low one, that gives them cash in a short time, they are more likely to accept.
There are also some sellers that you should avoid. Not every seller is as genuinely motivated as they make themselves to be. Some possible hints:
*they stall on having the home appraised or inspected
*is unable to clear up liens against their property
*does not own 100% of their property
*they push back the move-out date
*does not have a replacement property or back up plan
etc. etc. etc.
It is impossible to find the perfect seller. But it is possible to find out which sellers are legit, and which ones aren't.