How do you sweetly suggest a change in behavior?

For a best friend and room-mate...been living together for 9 months. There are quite a few things that I would like to have change in our living situation.How do you sweetly suggest a change in behavior?
Be polite but firm about the things that really matter. Here is where you really want to be a good diplomat so there are no hard feelings. For example, say %26quot;Jane, I know you love peanut butter, but I'd really appreciate a little notice when the jar's about empty.%26quot; Then ask what you can do in return.How do you sweetly suggest a change in behavior?
It depends on the behavior.



Remember, you are not the dictator of the room, and people are free to do as they please. So if you approach this wrongly, you might get a big F U in return.



If, however, what you are suggesting is eminently reasonable and necessary to a normal living arrangement, then I would just come right out and say it. For example, %26quot;I know you don't mean to, but you've been leaving your dishes in the sink a lot, and then in order to eat I have to wash your stuff and then cook and then wash it again. Can you do your dishes when you're done with them?%26quot; No need to be sweet. Just be clear, reasonable, concise and NONBITCHY.