Some people wrongly believe that if they want to know how to drink absinthe they must know how to make it. Two totally opposite things! Absinthe is still illegal in some countries. You can find an active production in countries such as: Spain, Portugal, Czech Republic and Denmark. In America we have a different story, not much is known about absinthe, and you have very little chances of finding a dealer who will to get it for you; so, the only thing to do is to learn how to drink absinthe and how to buy it, making absinthe at home is not a good idea.
A classic example of a homemade absinthe recipe is the following: First, you must add 100gr of wormwood in a liter of anisette or vodka. Second, let it macerate 48 hours in a warm place free of direct sunlight. The beverage resulting is so bitter and is usually accompanied with sugar. For a deeper flavored absinthe: First, mix 100gr of wormwood and 45gr fennel in a liter of rum or vodka. Second, wait a week. Third, after waiting one week macerate it with anise for another week and that is it!
You could be able to make a more highly-developed absinthe using more spices (you must consider a more complex process too): you can use wormwood, hyssop, calamis, melissa, anise seed, fennel seed, star anise & coriander seed. First, put the dry herbs in a large jar (wormwood, anise seeds and fennel seeds in equal quantities; add other herbs in less proportion according flavor intensity, this means that if your absinthe has a strong flavor you should use less). Second, dampen it slightly. Third, add 85% to 95% alcohol. Fourth, let it steep for seven days with occasional shaking. Fifth, add half the water and let it macerate for an additional day. Sixth, smoothly decant the liquid squeezing from the mass of herb the best you can. Seventh, soak the herbs with some vodka and squeeze it again. While making it, the absinth beverage must have turned to a dark greenish color. If it did not, you have to color it by adding mint, melissa, wormwood, citron peel and liquor-ice root in small quantities; finally, macerate the absinthe beverage for another two or three days. When all is said and done, storage of homemade absinthe is very important. If you want to drink a middle-quality absinthe and preserve its natural green color, it is recommended to store it in an area free of extreme temperatures. The optimal situation for mid to long term storage are the following: a permanent temperature fluctuating between 13º C to 18º C, complete protection from direct sunlight, vibration and using cork or screw on the cap.
If you want a good advice, it is easier to learn how to drink absinthe than learning how to do it.