Before deciding on groundcover, as Mad Gallica suggested, you want to think about use. Does it get a lot of foot traffic and if so, is it all over or in particular spots? Do you have kids or dogs who will be running or playing in the area? Do you want to have open level spaces for gatherings? Do you want to do more or less maintenance? Some groundcovers look great but either don’t do well with a lot of foot traffic or can be a trip hazard if folks are walking there. Some will spread quickly, but then need a fair amount of maintenance to keep out of paths, but others will spread more slowly and may need mulching and some initial weeding, but won’t be difficult to control once established.