I find that I tend to end up with multiple Finder windows open in OS X. A quick way to manage this is to merge them all into a single windows by clicking Window and choosing Merge All Windows.

Now that you have a Finder with multiple tabs, what better time to discover that using tabs in the Finder app is a great way to streamline productivity. If you open a window in Finder you can then open a new tab by hitting Command+T and you can then drag files from one tab to another.

To do this, start by drag the files of files from one Finder window into the tabbed area at the top, and wait for the app to switch over to that tab. Now complete the drag and drop by putting the file or files in the area you want.

If you want to bring up a new Finder windows quickly, hit Command+T.