The grouping may have unifying characteristics like: frame size and color, similar themes, size, dominant color, etc.
If the artworks are of varying sizes, try the following solutions:
- Align the paintings so that an invisible straight line passes through the middle of each of the artworks, connecting them visually in a linear fashion.
- Align the the tops or the bottoms of the artworks in a straight line.
- Create an imaginary rectangle or square, and hang the artworks along its edges.
- Center a larger artwork and hang smaller artworks around it in a symmetrical manner.
- Imagine two perpendicular lines and hang the artworks along them in a symmetrical fashion.