Visually grouping items in wishlist

Question

I am building a wishlist that allows the user to create groups of items without affecting the master wishlist (i.e. users can add an item to a group through tagging. One item can be on two different groups at the same time).

What is a visual/elegant way for the user to perform this task without multiple popups, overlays, drop-down menus etc like Pinterest?

There is value seeing the groupings in a moodboard fashion to see how the items play together within a group and how groups visually compare to each other. Imagine this is like building clothing outfits.

This is what I have so far:

Answer 1

Seeing your current mockup, I thought immediately of the Windows 10 Start menu and the way it lets users easily group and resize tiles without needing a bevvy of dialogs and prompts.

You could create a similar experience ...

... automatically add all wishlist items into a catchall group at the end
... tiles could be dragged around between groups
... dropping a tile between two existing groups to create a new one ... rename an existing group at any time