I always watch for the creeping phlox, candytuft and saponaria that look so perfect draped over banks and walls. White candy tuft looks good with anything, but its laciness is especially attractive under tall tulips.
I love plants that creep and weave and serve as groundcovers that stifle weeds, while uniting other plantings. At this time of year, I am always on the lookout for more different varieties of creepers to buy.
I also divide my cranesbill geraniums, low-growing campanulas, catmints and ajugas and scatter them around my garden.
The low-growing dianthus are very drought tolerant, so I'd like more of those in well-drained, sunny sites. Epimediums are good in shade, and once established they also tolerate drought.
Creeping baby's breath (Gypsophila repens ‘Rosa') is hardy zones 3 to 8 in sun and has pink flowers that start blooming in spring.
Lamium maculatum is also hardy zones 3 to 8 and has leaves with silver splotches so is attractive even when it is not in bloom. Most lamiums have mauve or pink flowers, but I am partial to ‘White nancy' as she is an absolute charmer and like all lamiums is vigorous and drought tolerant once established in shade or part shade.