Don't allow any of the white part of the walls to show in any room. Robots (not to mention Harry), can accidentally escape through these walls. In one level I've seen, there is a very small corridor with the white part of the walls showing, and it is very easy to get into a "for -show" cubicle and never be able to get back out.
For those of you that don't know how to actually play custom scenerios, just take these easy steps: At the menu, move the cursor to the top of the screen. The menubar will appear. Choose New Game In Custom World from the file menu. That's it. (from the Harry the Handsome Executive Developers Page)
To change the color of a locked door, make the door, then choose Edit Sprite. In the first info box, type the color you wish it to be. 0 = blue, 1 = yellow, 2 = green.
To make a door switch work with a door, lay down both the switch (sprite 95411) and a switch-door (sprite 951). Look at the sprite number of the switch. If it's 50, for example, you go into the first info box of the door and put 50 (the sprite number of the switch) into the box. That's it.
To make AOL disk throwers, put a 1 into the first info box of a dart-thrower.
Soda machine tips: Put the number of times you must kick the machine to make the first soda can get out in the first info box. Put the number of soda cans you want the machine to give in the game in the second info box.