Cool, glad to be of service! I honestly don't trust the results of a single reagent to fully identify a substance. Two reagents which produce a different color from each other in reaction to the same substance is ideal for seeing what's going on. well, ideal is an overstatement. Helpful is more like it. Many different substances produce similar color reactions with one reagent, but different color reactions for another reagent. I lucked out with the materials I had on hand, as some of the lysergamides produce similar reactions with Marquis, but Liebermann differentiated them noticeably.
I will put all the relevant information here and if it violates a safety rule on this forum I will take no offense at its removal by a moderator.
Marquis is prepared by the ratio of 9 parts sulfuric acid to 1 part 37% formalin solution. Because mixing these chemicals causes an exothermic reaction and the formalin is volatile, this must be done very slowly and it's advisable to do it in a glass container submerged in an ice bath. Never add the formalin to the acid, always add the sulfuric acid to the formalin solution. I measure "parts" as ratios of drops, usually preparing by doling out 10 drops of formalin into a small mason jar placed in a large bowl filled with ice cubes and a little water to assist in cooling the jar. Then I add 90 drops of sulfuric acid very slowly over the course of around 10 minutes. This is probably unnecessarily slow but I'd rather not have the formaldehyde volatize. This produces enough Marquis reagent for the testing of basically every unknown substance I might have at any one time.
Liebermann Reagent: 1 gram of Sodium Nitrite: 10ml Sulfuric acid. In this preparation, there is no avoiding the off-gassing of nitrogen dioxide, so it's best to do this outdoors. Weigh out the gram of sodium nitrite into a mason jar, and measure the 10ml sulfuric acid using what ever you have available to measure volume with. If you don't have anything available that can measure milliliters, just go with the density of sulfuric acid, 1.84g/ml, and measure out 18.4g sulfuric acid. Add the acid dropwise to the sodium nitrite, in an ice bath as with the Marquis preparation above.
Again, it might make more sense for people who haven't taken a chemistry course outside of high school to simply purchase these reagents from a trustworthy source.
Dancesafe.org has each reagent available for $20 or discounted combo kits of 4 to 8 reagents.
https://www.youtube.com/user/BunkPolice
I find that searching for the substance and the reagent will usually bring up Bunk Police's relevant video as the top search result, but this may change so here's the youtube channel.