What follows (from Barni F et al. 2007) is the recipe for the Weber formulation of luminol.
Weigh out 8 g of sodium hydroxide and completely dissolve them in 0.5 L of deionized water to obtain a 0.4 N solution (stock solution A).
Measure 10 mL of 30 % hydrogen peroxide and add them to 0.49 L of deionized water to obtain a 0.176 M solution (stock solution B).
Weigh out 0.354 g of luminol and completely dissolve them in 0.0625 L of 0.4 N sodium hydroxide solution to obtain a final volume of 0.5 L (0.004 M) (stock solution C).
Store the three stock solution in glass or plastic containers at 4° C, away from direct light.
Prepare the test solution by mixing 0,01 L of each of the three stock solutions to 0.07 L. of deionized water to obtain 0.1 L. of final working solution.
Decant solution into a vaporizer or sprayer and use immediately.
Tobe SS et al., J. Forensic Sci. 2007 Jan;52(1):102-9. doi: 10.1111/j.1556-4029.2006.00324.x.
Regarding how to perform a test, I found a discussion that might be helpful.
"The six different [color-change] reagents were tested against saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. For each of the presumptive reagents tested, a large piece of filter paper (approximately 100 cm2) was exposed to each of the substances being tested in 25 separate sample stains. These were allowed to dry for a minimum of 18 h. Each of the pieces of filter paper, and subsequent stains, were then tested with their corresponding reagent to see whether the substance caused a reaction."