||Select your mushroom, preferably one that is fresh, not damaged, and mature.
||Decide whether the spore colour is light or dark. The colour of the gills may give you some clues.
||Select a piece of card, white or black, depending on the selection as outlined above. Aluminium foil or a glass microscope slide also works well.
||Remove the stalk from the mushroom and place it gill side down on the piece of card or foil.
||Place a jar over the top. This helps to keep in the moisture as well as stop any air movement, dispersing the spores.
||Leave it to form a spore print. For how long? It will depend on the mushroom species. Try a couple of hours. If no suitable print is created, try again by leaving it longer, sometimes overnight.
||If you wish to keep the spore print for any length of time, then seal it in contact plastic, as used to cover textbooks. I have some that are over 15 years old that show no deterioration as yet.