Border help please

[Disneyvillain]

Hello, this is a west facing border, very heavy clay soil, slightly acidic. The shrubs are escallonia, rhododendron, azalea, euonymus and quince. To the right is a mature acer which will put that side in dappled shade. I would love some help with what else to plant here and how to arrange things. It all looks so bare and disjointed. Any ideas please?

Oh there’s a viburnum at the back left too!

When those grow big they will take up the whole space so I wouldn't add anything that is very long term. Some annuals or bulbs would help fill it out and cheer it up until the border is established.

A bark mulch would also make it look better in the short term, and improve the clay soil in the longer term.

Thanks for your reply @CatherinedeBourgh, I’ll try the bark mulch.