You could go for conifers such as abies which usually have glaucous blueish foliage and a compact habit rather than loose. There are several forms with an RHS Award of Garden Merit (AGM) which means they grow well and are easily available.
Berberis darwinii will give you small, glossy foliage and soft yellow flowers. It too has an AGM as do several other forms of berberis. Choisya ternata and choisya Sundance are evergreen with ornage scented white flowers when they are mature enough to flower. the latter has golden foliage so is sunny looking in winter. Both have AGMs.
Forms of cistus will give you papery white or pink flowers. Eleagnus has green and gold variegate dfoliage for year round interest and euonmous wil give you gold or cream variegation. You could also look up myrtus which has white flowers and shiny leaves.
If you have acid soil and enough moisture you coul dtry pieris forms which have coloured foliage in spring and then flowers. Pyracanthas are good for wildlife having blossom in spring and berries in autumn plus thorns to deter people form climbing your wall.
Again, if your soil is acid and moisture retentive you could grow rhododendrons in a wid evariety of sizes, leaf shapes and flower colour. Viburnums come in several evergreen forms and some which flower in winter.
If you want something you can clip and keep formal, have a look at taxus (yew) forms.
You can look up all of these on the RHS website - plant selector feature. You could grow a mix to spread the flowering times and provide year round nectar for bees and other insects.