In order to have successful seed germination, you will need to provide appropriate temperature, moisture, and relative humidity, and sterile conditions.
The ideal temperature for germination will vary depending upon the plant cultivar. However, most seeds will germinate very well when grown within a 70-80 degrees F range. Specific temperature needs of seeds will be indicated on the seed packet. If the temperature is maintained below or above the recommended range, the germination rate will be slower and fewer seeds will germinate. Most homes are kept at temperatures somewhat below the recommended range but there may be some areas in the home that are suitable.
Maintenance of a constant moisture level and nearly 100 percent relative humidity is important to successful seed germination. This can be provided by moist, but not wet, medium.
Disease organisms (fungi and/or bacteria) may kill seedlings during germination. Thus the medium, container, tools, and even the seed itself should be sterile. Commercial media are usually sterile when purchased. However, if the medium comes in contact with objects which are not sterile, it may become contaminated. Containers and tools can be sterilized by soaking them in a 10% household bleach solution (1 1/2 tablespoons/cup of water) for 5 minutes.