Dungeon Crawler - C++/SDL/C# - Representing Stairs Challenge

So, the game, at the moment is totally top down 2D, there are no camera angles, no isometric perspective, it's just all looking straight down at the canvas below.

So, one challenge is how to represent depth, I've seen some art styles showing walls rising from an edge of a square and away to the centre, so it looks as though it's a wall climbing up towards the camera.

And, this effect is built in, not by the game, but by loading the pictures/images from disk, so anyone can draw like that.

One thing I can't do however is I can't draw, not very well, not on a computer.

And the next challenge facing me is how to represent stairs, if I can't do it easily with a single tile, do I need to make stairs which take up several tiles and have isometric effects to them, or do I need to increase the size of the tiles?

You see, there are options, which work to represent top down stairs...

That looks right to me, but it's done with shadows, alpha and importantly to work it all needs more than 70x70 resolution...  The same trick for me, using gradient brushes, at 70x70 comes out like this:

It's not the same is it?... No, I didn't think so.

Other options are to make stairs as I would with a biro on a table top map:

But, again this needs more pixels per tile, and definitely needs more than one tile.

Stairs going down are also a challenge, they need just as good a resolution which my tiles don't provide:

From http://www.cartographersguild.com/showthread.php?t=22407

Suggestions on a postcard please.