Train climbing roses as they start to grow, so you end up with a lovely even screen of foliage and flowers across your wall.
Roses flower most prolifically when their stems are held horizontal, as that encourages them to send out lots of smaller flower-bearing sideshoots. So aim for a series of branches arching out on each side from the main stem, tied in to their supports at regular intervals up the wall.
If you're growing your roses up a pillar or obelisk, the same effect can be achieved by circling the main stem around the pillar in a spiral, instead of training it straight up. This holds the stems at about 45° from horizontal, enough to encourage a really generous display.
There are dozens of lovely climbing roses at your favourite garden centre, all of which respond well to this treatment.
'Dublin Bay' is a sultry deep scarlet, while 'Golden Showers' is a sunny yellow. If it's scent you're after, 'Madame Gregoire Staechelin' has masses of beautifully perfumed pale pink flowers on almost thorn-free stems.
'New Dawn' is a robust, pale pink climber which tolerates some shade; and 'Cecile Brunner' is the one for true romantics, with its frothy double flowers like a cascade of little pink puffballs.