So many mistakes are made when it comes to using heroin or other opiates (this targets injected opiates), so here are some suggestions and warnings for people.
Being addicted is quite unpleasant when it comes to withdrawal. (See previous post.) If you're going to use in the first place, do not use more often than 8 hours of a day, and wait at least 72 hours until you use again. (Sources - heroin helper, other users & addicts.) That takes care of the physical part. But watch out for "mental" addiction that makes it easier to forgo the rule. If your clean days seem less worthwhile than the day you use, a problem is developing. (Source - Gledwood's old blog.) Consider cutting down your frequency, or stopping altogether.
Do not share not only needles, but equipment as well (cottons, cookers, etc.) Be very wary of getting "clean" needles from other people - look for it coming out of a sealed package, with the cap sealed on, ensure it does not have a little spot of blood, and in the United States at least here - a clean needle's plunger is not pressed all the way to the bottom, it has about 5 units or so of space/air in it. Better to just get your own. And if other people are injecting in your house, WATCH what they do with their needles, so they are not confused with yours. Do not underestimate the potential for disease, do not trust that people would not infect you on purpose. (Source - http://memoiresofaheroinhead.blogspot.com/2011/10/killing-fields.html)
Abscesses are terrible! They come from impurities (little pieces of dirt, cut in the dope, pill fragments, etc.) Filter, filter, filter! Then LOOK at the needle to see if there is a little piece of cotton on it, pull it off, wash the needle in full-blast water. (*Cotton fever can aslo be avoided this way.) Wash it even if you don't see anything. Then, keep the cap on until you are about to inject. Whenever possible, clean off the spot you're going to use for injection, preferably with an alcohol wipe. Avoid intramuscular injection and skin-popping if possible, and if you get blood in the syringe, avoid putting it back into anywhere but a vein. If it starts clogging/coagulating, it's best to dump it back into a cooker, add water, re-cook, re-filter. While injecting into a vein, if it starts to hurt, pull back and check if you're still in the vein, and re-register if necessary. (Sources - other addicts/users, bluelight, heroin helper.)
Veins, for some people, can be extremely hard to come by. If a person uses for long enough, even the people who started out with "ropes" very well may have vein issues. Avoid the whole "track mark" thing - injecting into one spot til it stops working, then following that vein all the way up til the whole thing is dead. Rotate injection sites as often as you can. If/when you begin to get to the point your veins are dying out, avoid "pointless" shots. Don't do cotton/filters/rinses unless there are no other options & you're ill. Don't shoot up just for the hell of it, and there's no reason to shoot up 8 + times a day - pretty much anything after 5 or 6, you barely even feel it. Purchase needles frequently, use fresh ones whenever possible, and switch needles if you've made several attempts to do one injection. Dull & barbed needles do further damage to veins. (Sources - other addicts & users, bluelight, own dying veins that were small & difficult to begin with!)
Eye don't have the absolute best answer for China White, but at least when it comes to tar - COOK your dope. Some people say that it shouldn't be cooked because "Heroin is water-soluble and cooking it makes the impurities break down & can also get in your mixture." Well, bacteria's pretty tiny, too, and can easily get into your needle. Heat can kill bacteria. Think some Mexicans haven't rolled an actual piece of FECES into an extremely big block of heroin, in their middle-fingered spiteful salute to Americans? Ha! Think again (source - someone who's been there for an instance like this.) (And before the comments just fly in about "how can you still use it, knowing a story like that - disgusting! Well...first off, there's that whole heat killing bacteria thing. And think you've never been served food after someone hasn't washed their hands? It's more common than you think. People spitting in food does also happen. Do you still go out to eat?) This bacteria can lead to tissue or blood poisoning. This can be fatal. (Source - the hooker who used to come over to beg for free cottons off of me, which eye willingly provided, last year eye was 100% disease free which is still true unless someone slipped me something during sleep or switched a needle while eye wasn't looking, and eye DO watch - which is possible but unlikely... but she also didn't care & was under the mistaken impression that "once AIDS hits air, it dies." You could not tell her differently. She boiled down cottons, but eye never saw her cook actual dope. She died of MRSA, an infection she developed from uncooked dope, about six weeks ago.)
Be very wary of letting someone go off to score drugs for you if you do not know them. Especially when they are an addict, especially to a different drug! It's especially suspect if they say they'll do it for free or $5 or less. (Source - own, embarrassing! stupidity.) It tends to be less likely to happen if it's someone like say, your long-term neighborhood homeless person with whom you have shared previous conversations, and you offer to get them a bag. After all, you see them pretty often, they're unlikely to run off somewhere, and if they're getting something too, there's no real reason to screw you. Eye hear you can also make similar offers to people at methadone clinics, but have never attempted it, myself.
Um... don't drive or operate heavy machinery while nodding out. (Source - common sense.)
"Drugs are bad, m'kay?" (South Park)
And now, back to your regularly scheduled program.