I love my little solar uplights, I have two in my back yard, highlighting speciman plants. Maybe they're not truly "up" lights, but I point them upwards.

Of course, if you don't live in a very sunny place like I do, you'd want to do low voltage.

You'll need to show "the garden." Light must fall on something and in order to make suggestions, we'd need to see what is lightable in your yard.

I think best practice is to put different kinds of light, anyway -- uplight, downlight, path lighting, safety light, etc.