Door problems occur when they don't open properly because of misleading hardware. If it needs a sign for pushing or pulling, then there's probably something wrong with the design. Switch problems occur when there is a bad mapping. Arrangements and labeling are important.
The principle of visibility is to make relevant parts visible. The principle of feedback is to give each action an immediate and obvious effect. The principle of visibility is repeatedly violated in everyday things, usually for aesthetic reasons (e.g. switch for typewriter on the side, cabinet handles hidden). Visibility makes all the difference (e.g. on-screen VCR programming). Nothing succeeds like visual feedback, which in turn requires a good visual display.
There are some suggestions for using new technology: Having the CD contain the information of it's own name for the CD player to display; displaying the names of TV programs and having cooking instructions in machine scan-able form on food packages so that microwaves could automatically cook them. When things can't be made visual, then use other stimuli, like sound. Care must be taken as sound effects can get cute rather than useful and eventually annoy and distract users. Advantage of sound is that it can be detected when visual attention is elsewhere. Absence of sound (from background) can also be useful.