Once you have created your lists of collections you can add some of the search results into them.
First, make a search. On the search results page, please open in the preview mode the file that you want to be added into your collection folder. In Preview on RHS, please go in the section called 'Action'. Once you are in this section, bellow you'll see the Collections dropdown menu and you'll be able to choose the ones you would like to add to a folder.
You can also remove results from a list directly from this dropdown, just uncheck the checkbox .