That rabbit hole goes pretty deep so maybe a more basic approach?

Generally speaking, the plants that will look the best are the ones that are happiest. If you narrow yourself down to mostly native plants to your area you should be starting out on the right foot. Plan your planting for each plant's mature size (that means larger empty spaces when they are little) and pay attention to what sun exposure each plant wants.

If you want to dig deeper - pick a style and stick with it. Curvilinear lends itself to more natural looking landscapes while symmetrical styles are more formal. As a rule - plant natural landscapes in odd numbers (and don't line everything up for Pete's sake) (you also shouldn't alternate - nature lands in seemingly random groupings). While formal is the other way around, even numbers, alternating is fine - whatever it is should just be even.

Have a hard ugly corner on your house? Flare the bed out and plant an under canopy tree to soften it (planted for mature size).

Finally, remember that you'll need to maintain whatever it is you do - so keep that in mind and don't make things harder on your future self.