Smartest way of editing/making a "compilation" film from a lot of new and old projects for a client.

Hi, I am going to make film for a client that I have been working with for a couple of years. Every film that I've made for them are more or less on seperate harddrives. So the way I would go about it is to collect all of these projects on a new harddrive to get hold of my edits and grades to use for this new film. 

Then import every PP project in to the new one that I will create for this new film.

But I'm quite sure that there is a smart(er) way. 

If you have any clever suggestions please let me know.

Best

Jörgen