Koosh: I suggest doing a search of this forum, as well as a general search on Google. Not only have there been many many threads and online articles [as well as FAQs] about the subject, but in one of the threads in this forum [about 2 years ago maybe] I posted a link to a municpal drug authority in the Netherlands. This site has an actual video as well as easy to read instructions on how to smoke heroin correctly and safely.
One thing you should remember though, is that heroin in its unaltered state is not fit for smoking [except "blacktar" and "homebake" forms."
There is a grading system consisting of 4 numerals to classify the different forms of heroin [devised by the US Govt.] Heroin #3 is the form expressly made for smoking. Unfortunately, #3 is not really produced anymore and is almost NEVER available in the Western Hemisphere, and very rarely outside of S.E. Asia.
In Europe, including of course the UK, the most common form of heroin is Heroin #2, which is actually a freebase. This too can be smoked but not optimumly. For all types except #3, "Homebake," and "Tar," you need to alter the substance. The problem one faces is that heroin's melting point is far too high in its unaltered state. This means that the heroin takes far too long to vaporise resulting in most of the heroin being wasted. This can be recitified by throughly mixing caffeine hcl., with the heroin in a ratio of 60:40, with 60 representing the heroin.
Fatmatt: If you purify your heroin you know exactly what you are getting. You should also know that there counterfeit Oxys on American streets.
Good luck.
Caffeine will lower your melting point and help you to have a much better expereince.