I recently installed an interior railing in partnership with Iron Horse Metalworks. This was a simple railing, with 5/8″ round pickets glued into the treads and 1 1/4″ round posts. Whenever we do a railing like this with no bottom rail, we like to erect the cap rails and posts first, and then TIG weld in all the pickets individually.
This allows us to have a good layout that matches the stairs well and a very clean finished product.
The offset around the second story floor is as common situation in interior rails. Code requires the railing to be continuous from landing to landing, so the railing must be connected even when there are walls in the way. I like to use gentle curves to do this when possible, as it looks nicer and is less likely to be a hip bruiser.
The corner turn is a nice detail, as it also incorporates an up easing to match the elevation change of the stairs. Again, gentle curves are used to make the transition.
The bottom features a hand forged lambstongue. We never use the cheap cast terminals, we always make a cap rail termination that works with the style of the house.