Bevelling skirting boards to match architraves
I did this with my Philadelphia home. Below is the best picture I could find.  It's near impossible to tell from the picture (and this is not the most flattering angle), but the baseboard is thicker than the side case molding.  I simply beveled it to even with the casing at about a 45 degree angle with a block plane.  I did not use shoe molding; instead opting to scribe the baseboard to the floor.  The bevel actually helped the install look more detailed and "craftsman-like", in my opinion.

By the way, just in case it needs to be said: You will need to use real solid wood to do this.