Write an article based on this "Gather your tools. Dig a test pit. Start to take the soil back one layer at a time. Keep an eye out for soil changes. Dig as far as the evidence takes you."
Ideally, you should have a shovel, a medium garden trowel or a small cement trowel, a scraper and a brush. If you are lucky enough to have any finds, you should have a tray to keep them in, a camera and a ruler or yardstick. It is also recommended to have a tarpaulin or a wheelbarrow to add your soil and any turf-grass or paving stones onto without making a large mess. Otherwise known as a sondage, this pit should be a few feet (60-90cm) across, but generally no larger than a metre across each way, otherwise it can become too large a job that requires a long time to excavate. Start by measuring with string and pegs, marking paint or a frame. Lift the turf or paving stones. Put these aside neatly on the  tarpaulin so you can easily put them back afterwards with minimal effect. After you have lifted all the turf, check the soil to see if there is anything there. This layer will be the most recent and will be unlikely to have anything very old, although you may find something a few decades old such as an old coin, discarded bottles and other recognisable items. Photograph anything interesting you may find. For young children,  anything can be interesting, including old bottle caps and scrap, but  genuinely interesting finds are directly related to human activity, as  well as dating evidence. As a very rough metaphor, imagine a loaf of bread. You cut the bread in even slices rather than make random holes on the loaf and that's roughly what you are endeavouring to do, by digging layer by layer, revealing even slices. This is the slower way of doing it, but it is arguably the proper method to reveal each layer and get an understanding of the contexts.  For most excavations, it's best to obtain a soil sieve from your local hardware store and check the "spoil heap" and/or hire or purchase a metal detector to check for small traces of metal objects. Both ways provide opportunities to find the subtle clues of history. The key method of layers is that if a coin from 1970 is found in that layer, then it's highly improbable that the layer is older than 1970––unless it was buried there––which in itself is an interesting discovery. If you find a very old layer, yet it has modern debris in it or below it, then old soil may have been shifted to that location, or there has been modern disturbance. This inconsistency is all part of the story. The study of layers is often referred to as Stratigraphy and for very complex layers, it can be connected with paleontology.  If you find darker patches, this may be remains of charcoal; its presence may be as simple as a bonfire or campfire remains, or alternatively an older dumping ground for kitchen and other waste which has enriched the soil. Small or isolated patches of burnt material are more likely human made rather than a seasonal; naturally produced fires typically would form an even ash layer that can be found when digging  several pits in an area. Intense or prolonged burning (such as an ancient hearth, forge or demolition) often leaves red traces in the soil.  Other changes to the soil such as lighter and darker layers can show either natural accumulation, chemicals or metals being dumped, or humans digging holes for a fence post, digging a trench to bury something or part of land management, such as building an earthen or stone wall. The key to being a good archaeologist is to decipher these changes. Photograph anything you uncover using your ruler as a scale reference. In particular, keep records of anything that can indicate unknown human activity, or activity that you wouldn't think is normal in a household backyard. It is best to record everything you find and observe, including depth and location in the test pit. Be mindful about the soil types. If you find soil that is different or not naturally occurring, this is a find all on its own. It may be something as simple as someone digging a garden bed using introduced materials or it could be something more complex, such as a quake or a novel building foundation; deducing from the earth what people in the past were doing there is what archaeology is all about. If you're likely to dig more than 1 foot (30cm) deep however, it's generally best to call in additional help, or leave the test pit and ask your local school, university or local historical society to get involved. Deep pits may need structural support for safety and if the water levels are high, may fill with water and be unsafe or just very difficult to excavate.