Default file-save and file-open locations

I wish to save files to and open files from the last folder I used folder. I cannot locate any settings dictating my open and save preferences.

First, I know when I turn the computer on, there is a certain default destination when I open a file for the first time. I'd love to change that setting because until recently, it was usually "All My Files" no matter what program I was in. But recently for no apparent reason, it is now my "Documents" folder. I made no changes to this setting because I can't find it.

Additionally,

1. I want to open a document, make changes, and then be confident that no matter what Save method I use (Command-S or File-Save) the file saves to its destination folder. But this doesn't happen.

2. I want to work on File-A from Folder-1 and open File-B from Folder-1. But when I click File-Open, I am taken to "Documents", not Folder-1. Sometimes Folder-1 is a few folders deep in Documents and clicking away is annoying. And yes,, I can click the folder from "Recent Places", but that's just inefficient. why not just open from the last folder I used?

I hope there's help out there.

Thanks,

Tricia