First thing, get a soil test done; Texas A&M offers this service (web page here). This is essential if you're considering azaleas or rhododendrons, as they require acidic soil.
The type of shade you have makes a difference - some plants do great in dappled shade and fail in "house shade". Large-leaved trees like Norway Maple (if you have those in Dallas) or plane trees/sycamores have deeper, less dappled shade than trees with compound leaves like locusts. It will help you with selecting shrubs if you know what kind of trees your neighbors have.
When it comes to selecting a shrub, I'd recommend that you follow the landscape design "rule" of "right plant, right place". This means that, if you have a four-foot wide planting bed, you plant only shrubs that get no larger than 3-4 feet wide. This reduces maintenance to pruning only when a branch breaks or gets a bit out of hand, as opposed to spending an hour or three several times a year trimming and shaping a shrub that's too large for its space. The shrubs will be happier with less pruning, too.
This site, called 'Best Shrubs for Shade in North Texas' lists a variety of possibilities for you. Note that it does not go into much detail about things like cultivars and shrub sizes, but I think that's actually a good thing because you can take the list to a local plant nursery (not a box store) and use it as a guide to get more specific information. For example, it lists Viburnum as an option for you, but that genus has cultivars ranging in size from 3 ft x 3 ft to 10 ft x 10 ft - which to pick depends on the amount of shade and the size of your planting bed and, perhaps, your soil type and drainage (the soil test will help with that info).
Again, go to a plant nursery (preferably one that specializes in or has a large selection of shrubs) rather than a box store like Home Depot or Walmart. You may pay a little more for the plant, but you're getting the education and experience of the sales staff, coupled with better overall care of the shrubs, for your money.
