I have two keyboard shortcuts that I just found. Keyboard shortcuts are of course always shown in the menus of applications but I thought I’d mention these two.
Here’s the first one. If you have a folder as a stack item on your dock, command clicking it will immediately open the folder instead of doing the usual stack animations.
The second one is, if you select a file anywhere on the desktop or in a finder window and press command+shift+T you’ll add that item to the dock as a direct link to that file or as a stack if it is a folder. Command+T itself will the selected file as a sidebar item in Finder.