What tree for front yard facing North?

There are literally hundreds of shrubs of all sizes, like the ones I mentioned earlier, but what gets chose depends on the amount of room for them, and the time available for maintenance, and the climate and soil are also factors in the eventual size anything reaches.
Ones which can be reliably pruned are always worth considering, and many Hebes can be iffy if you're in a colder, wetter part of the country like I am, because they don't always recover if hard pruned. In milder, drier areas, they're usually fine.
If you intend planting them near the tree itself, that can be problematic due to the lack of moisture for them, and more shade, so that has to be considered too.