The mudroom is still not finished so meanwhile I can show the drawings I made before the building process started. I used powerpoint and pasted screen shots and pics of doors, cabinets etc.
The mudroom was dimensioned after the cabinets. If you are going to build new walls any way, this is the cheapest way to achieve a custom built look. We did the same for the kitchen, laundry room and library in our old house. The windows and doors in the library were all placed after the IKEA Billy book shelves. The kitchen and laundry room was dimensioned after standard kitchen cabinets. After all, it is the same cost for a door no matter where you place it.
The Elfa system comes from the Container Store and I used their web tool for planning and then did screen shots that I cut and assembled with gimp before pasting them into powerpoint. (Do I dare to say that the super convenient Elfa system comes from Sweden? I grew up with it in the 60's and 70's and some of the old pieces are still in use in our house.) I took the drawings along when ordering the parts at the Container Store and it went very smoothly.
During the building process I taped these drawings to the walls to show builders, plumbers and electricians where to put what. I can easily imagine a room from a house plan, but to communicate a complicated (and not-so-common) layout, these sketches were good complements.