Not to mention the legality issue , when performed by individuals who are not trained chemists, methamphetamine manufacture can lead to extremely dangerous situations.

You can read about various ways to manufacture methamphetamine  in http://en.wikipedia.org/wiki/Methamphetamine#Production

A completely different synthesis procedure involves creating methamphetamine by the reductive amination of phenylacetone with methylamine, both of which are currently DEA list I chemicals (as are pseudoephedrine and ephedrine). The reaction requires a catalyst that acts as a reducing agent, such as mercury-aluminum amalgam or platinum dioxide, also known as Adams' catalyst. This was once the preferred method of production by motorcycle gangs in California, but DEA restrictions on the chemicals have made this an uncommon way to produce the drug today.

Other less-common methods use other means of hydrogenation, such as hydrogen gas in the presence of a catalyst.