I've always found multi-colored impatiens and a small leafed ivy (especially the variegated kinds) look great together and do well in shade.

My favorite for shade is coleus. Hostas do ok in containers too and the variegated kind is nice.
You can also try calladium.

Hosta toward the back of the container, and impatients bursting around the rest! I did a container like this 2 years ago and it looked really pretty; I also planted ivy at the front edge and it trailed off the side nicely.

Also, coleus! I grew this last year from seed and it did VERY well.

I have a north-facing front door and porch too. I use bought plants nearly in flower - they add seasonality and color to the familiar shade-loving plants.

Watch your porch, and see if it gets just a little morning or afternoon sun. By my porch, a touch of morning sun is enough for hellebore and a plain old daisy bush, and often enough for bulbs (especially if you rotate the bulbs to sunnier areas after a year on porch-duty).

I once had a tiny-flowered species camellia which filled my shady porch with fragrance. Years ago, in another country, and I forget the name of the camellia, sorry.

Other flowering fragrant plants that will do OK with just a touch of sun or open shade - violets, planted in a raised container so that you can really enjoy the fragrance, heliotrope, jasmine, nicotiana...in my shady porch, geraniums do surprisingly well, and of course hellebores.

I have lacecap hydrangeas in shade elsewhere, but they sprawl, so for a porch you might look at a climbing hydrangea.

Parsley, mint, and lettuce do quite well in containers on my porch too!