I especially like climbers with a habit that gently winds up the growing surface without becoming too dense. Clematis ‘Frances Rivis’ and Trachelospermum (star jasmine) can offer interest in the form of small ornamental foliage that isn’t too opposing.
The Hedera helix ‘Ceridwen’ variety has variegated leaves that display green and buttery cream shades instead of blanket colour.
As well as decorative climbers, you might consider planting some productive crops like cucumbers, climbing beans, peas and vine tomato. These look really striking and deliver fresh harvests throughout the season.
Or go for tree trained against walls, like fan cherries, espalier apples, or cordon pear specimens. With limited space, you add height using raised beds—these offer more planting space because the soil is mounded in an arc.