I would highly advise you against trying methamphetamine for the first time, it's one of the easiest drugs to get hooked on, and it might not be so cheap in Europe but it's dirt cheap in the USA, and goddamn I've watched it unfold as one of the nastiest epidemics this country has ever seen. Using it in moderation is often a ton more difficult to achieve than it is to talk about, depending on the ROA you choose, I highly recommend the rectal ROA, where it is absorbed completely without the need for IV administration, still achieving a rush.
Morphling got a lot of the bullet points, I'll summarize and add to his post:
-SLEEP IS IMPORTANT. Meth will try to change your perspective on this, and it often succeeds. Tread carefully.
-EATING IS ALSO IMPORTANT. Meth will also change your perspective on this, and seriously you should take my word for it, something that is capable of making you think you don't need to eat or sleep to be superman, is a fucking dangerous drug that should only be taken with the utmost respect for it's power.
-As far as dosing goes, I have always been satisfied with microdosing with this chemical, it's the way I function best while on it. For me, the best target dose range is 15-30mg, but my most commonly administered dose by a landslide would be 20mg, and NO REDOSING. Redosing is a recipe for disappointment, disaster, and psychosis.
-Keep yourself hydrated, remember that drinking huge amounts of water is actually counter productive, it's of no use unless your getting electrolytes and nutrients to retain the water.
...I'd HIGHLY recommend the use of anti-oxidants, vitamins, and whatever supplements your individual body chemistry may require for minimal disruption with use of such a powerful CNS stimulant.
I personally will never take street grade methamphetamine again without having the following on hand: Complete Multi-Vitamin, 2g of EPA+DHA content in Omega-3 fatty acid capsules (this usually means taking 3-6 / a handful of gelcaps at a time) depending on how much EPA/DHA your Omega-3 fatty acid capsules contain. The higher % of the Omega-3s that are EPA/DHA the better.
-Definitely take a few grams of bulk (or capsulated, if you can't handle the taste/texture of) virgin/unprocessed/unrefined coconut oil (VCO) via the oral route, to promote GI health.
-Last but not least, perhaps most importantly, Chelated Magnesium. The folks over in Advanced Drug Discussion have a great thread, it's called the Amphetamine Toxicity / Tolerance Prevention thread, and it explains how Magnesium works to make amphetamines behave and feel much "cleaner".
-I personally have noticed such a gain in the positive effects and such a supression of the negative side effects associated with methamphetamine when I take my Chelated Magnesium with or before my dose of methamphetamines, however it is of note that there have been peer reviewed studies / literature which report finding magnesium to be absorbed much more completely when taken in the evening or at night, which is pretty much the worst time to take amphetamines and live a normal productive functional life IMO.
-Electrolytes: can be replenished via Gatorade or something more to the point like Pedialyte, Ensure / nutritional drinks, protein shakes, salts, etc. CRITICAL in your experience, both during and after using methamphetamine.
-SLEEP: coming back to this one. No matter what, you must sleep every night. This is my advice. Other people may not agree with it. I believe that binging on methamphetamine is what gives it such a bad name, and it's compulsive redosing associated with certain ROA's (IMO, smoking it or snorting it are some of the most fiendish ways of consuming it, vs. rectal or oral dosing which are wayyyyyy smoother, last significantly longer and have much less of a crash, if any, *heavily dose dependent- how hard you crash is heavily dependent on how much you've taken and how much sleep/food/care you've given yourself.
-FOOD: Means real food. Not microwaved hotpockets or drive through fast food from the local Dennys or Taco Bell.
-HYDRATION: Means purified water or a therapeutic equivalent (like coconut juice/water) I.E., Mountain Dew or any carbonated soda is not what I mean when I say hydrate.
-HYGIENE: I cannot stress this one enough. When your preparing to go to sleep, take a nice long shower where you clean yourself thoroughly. Cleaning yourself thoroughly does NOT involve obsessive/compulsive picking at your skin / looking at the mirror searching for imperfections you think you can make better via brute force, because that will accomplish nothing but aggravate your skin causing or worsening acne, lesions, blemishes, etc. If you think you have bugs under your skin, you've been up for too long and should absolutely not pack another bowl. There's nothing sexy about meth psychosis, and sometimes you may (or may not) find yourself in front of the mirror for extended periods of time on methamphetamine attempting to correct your every imperfection, real or imagined, leading to a significant decline in your sex appeal, self-esteem, and of course, your hygiene. So take a hot shower before getting into bed, it helps you to fall asleep too, which is not impossible, even if your body feels like it's coursing with adrenaline (which would mean you took a very high dose.... not off to a good start...)
So yeah, to recap:
Sleeping every night, eating every day (Eating junk/processed food does not count as food*)
*If you're wondering whether the meal you've set out for yourself is junk food READ THE INGREDIENTS and here's a cheat sheet for signs of JUNK FOOD / ingredients which should raise red flags, and have you reconsider the meal altogether: partially hydrogenated fat/oil. If the first few ingredients are sugars, particularly the worst culprit: High Fructose Corn Syrup, dextrose, sucrose, all of these are sugars that rot your teeth....
...So.... move along to the next option if you don't want meth mouth, which is the result of neglect for one's own personal hygiene and safe eating habits, instigated/made worse by the methamphetamine which dries out your mouth, making it more prone to tooth decay, cavities, and other dental problems. A home-made, light salad, sandwich, and a tall glass of milk***** will do you exponentially better than a 32oz diet coke and a bag of Funions and a hot pocket.
*****Be advised that milk is alkaline, and alkaline urinary pH has been linked to the level of substantially potentiated effects of (d-meth/dextro)amphetamines.