You can clean any porcelain cooktop with a non-abrasive cleanser. Note: Don't pour the cleanser directly onto the cooktop. Instead, put some cleaner on a soft, damp rag, and then wipe the surface.

You usually need to replace the drip pans or bowls beneath the grates on a gas cooktop/range and beneath the heating element on an electric cooktop/range every 2 to 3 years. Once they're stained, it's usually not possible to clean them completely. 

Never wrap your pans with aluminum foil because this can cause a shock/fire hazard on an electric cooktop/range and will disrupt the air flow for proper flame on a gas cooktop/range.

If your oven is self-cleaning, consult the owner's manual for instructions on how to use this feature. The self-cleaning feature works by heating the interior of the oven to a temperature so hot that it incinerates the residue inside the oven. The self clean cycle cost less in energy cost than the purchase of a container of conventional cleaner. Normally, it is not a good idea to clean the interior of a self-cleaning oven with a conventional oven cleaner; however, refer to your owner's manual or contact the manufacturer of your oven for further information. To clean a non-self-cleaning oven, use one of the many oven cleaners that are available at grocery and hardware stores.