You need to think three things- aspect, seasons and height.
Are you planting only in tubs? If so, you could still train some climbers up the walls if you can put up some trellis.- clematis, winter jasmine, small honeysuckle perhaps,climbing rose. If you can plant in earth, you could add in some ivy. You could try a tree fern if you have more space but they can be too big.
You need to find out which direction your yard faces and how much sun it gets- and choose plants accordingly. Plants that love sun will not thrive in shade and vice versa.
You need to think seasons- so tubs can be planted with a mixture of spring bulbs for colour, small evergreens such as hebes, azalea and dwarf rhododedrum ( use acid soil not ordinary compost), small acers, hostas.
For summer you can either use annuals, the usual gernaiums, lobelia, fuschia etc, or buy pernennials that can go into tubs- small plants such as dianthus , all the hardy geraniums, dwarf roses, ...
have a look at www.crocus.co.uk for some ideas.