There really is no general rule for making offers.
Your negotiation strategy will largely be determined by how motivated the seller is to sell the house and by how much buying interest the home has garnered during open showings.
If the house has great curb appeal and is in a desirable area,
you don`t want to make a stink bid and risk insulting the owner.
you don`t want to offer too high and miss the opportunity you had for getting a lower price.
your best bet is to do some due diligence and comparative research.
Have your real estate agent do a search on how much houses on the street or in the neighborhood have sold for in the past month,
or 6 months.
If you discover that homes in the area tend not to stay on the market for very long,
and that they usually get very close to their asking price,
then you have some information to work with before you propose a buy offer.
If you find that homes are selling for much less than asking,
you know what to do.
But make sure you ask you agent,
or if you don`t have an agent,
ask a friend who knows someone with access to the home listing service and see if they will do you a favor.