There is something alluring about walking on a path of stepping stones with a touch of vegetation in between the crevices. It could be the great visual qualities of the hard material’s texture and color contrasting with the softer and organic qualities of the planting material, but nevertheless achieving such looks requires research and preparation.
It is wise to choose a paver material that suits the style of architecture of your home which you can then select a groundcover that compliments the material you chose. Ideally you want to use a groundcover that is tight and low mounding that allows you to walk on the pavers and also one that is suitable to your garden’s environment.
Below is a small list of groundcovers you can use in between your stepping stones:

Blue Star Creeper (Pratia pedunculata) has tiny deep green leaves with light blue flowers that dot in spring. It is a stepable groundcover but be sure to let it get well established before giving it too much foot traffic.
Dymondia margaretae has spidery leaves that are blue-gray on top with a silvery sheen on the underside and a sweet yellow flower. It can withstand light foot traffic and once established it becomes a barrier for weeds.
Sedum rupestre ‘Blue Spruce’ forms a mat of blue-green leaves arranged around the stem like spruce needles.
Baby ’s Tears (Soleirolia soleirolii) is a unique moss-like groundcover with tender leaves that you don’t want to step on. Do be careful of where you plant this one because if planted near a lawn, it will spread and overtake the lawn area.
Carpet Bugle (Ajuga reptans) forms a low carpet of narrow leaves, brightly splashed with green, pink and cream. Short spikes of deep blue flowers appear in mid to late spring.
Herniaria glabra (Rupturewort, Green Carpet) is extremely drought tolerant and has attractive green foliage that turns bronzy red in winter.

Remember that there is maintenance required to achieve this look. You must pull the weeds that pop up from time to time and keep the groundcover in check with pruning! So if you decide this is too much maintenance, decorative gravel is always a suitable alternative.