A set of dental tools (angled mirror, pick & scrapper), found at CVS, etc. Mirror aides in inserting new needle and being able to see into the bobbin area and below it for lint build up. Also Q-tips are handy for removing bits of thread and lint, either dry or slightly dampened, from the bobbin area and below it.
*Caution - Using any magnets around computerized machines could cause problems unless you know the computerized parts have been sealed to prevent magnets from harming them.