Great suggestions, Zuzu and Sue!
Several of my lilacs have 'Betty Corning' clematis winding through them. I have a 5' tall deciduous magnolia (can't recall the name, sorry) that blooms white, so I planted a double white clematis next to it. Some years, they bloom together. Most years, the clematis acts as a season extender for the magnolia. I have a new orange climbing rose, 'Above All', that needs a purple clematis, so I think I'll plant a 'Polish Spirit' with it. I wonder what it would look like with a bright pink clematis, though? Wild?
