I’m sorry my english is bad!
I want to create a collection of my profile. I created a collection. I can not projects in the collection. show how the lower down in the projects collection.
If I understood your question correctly as soon as you create collection you may open any item and on the right bottom part of the item page select which collection you want to include reference to this item (“My private bookmarks” drop-down list contain all of your collections) and press “Bookmark this!” button.
Best Regards, Andrey