Reference Books and the Internet: Educate yourself with reference material and real world handling of original pieces, record notes of what you see, most important study well known fake decorations. Download images from auction houses and websites. Good reference books can be expensive, some cost up to $400.AUD, but worth every cent for the serious collector. Having said this, there is a wealth of free information on the world wide net available, just by searching through Google, type in what ever you are looking, for example German Medals, Soviet Medals, British Medals, Military Orders, British Swords, German Swords etc. There are hundreds of articles written, and thousands of pictures of every medal and piece of original militaria ever made in the world. You will find precise information on the internet, sometimes even articles written by world experts to make an informed decision just by sitting at your computer. Become what you have always always wanted to be, a professional serious collector.
Spend more and buy the real thing: The bottom line, as we would always suggest isto spend more money from a reputable well known dealer in the collecting community, and buy the real thing. For instance, if you collect German items you know yourself how rare most original pieces are: it is far better to bypass something offered to you at 70% off the regular collector's price (but with a fishy story - or a suspect dealer) but rather spend 100% of the known collector's value and get the real thing.
If you collect genuine military collectables there is no such thing as a real bargain. If it is genuine it will sell for 100% the correct collector's value.
If in doubt, always ask the seller if the item is original: A common sense approach, always ask the seller the most important question - Is the item original? Ask from what time period in history is this item supposed to be from? Is it made from the correct materials used during that time in history? Is it un-tampered with? For example a genuine German WW2 Combat Helmet in original condition, ask if it still has the original factory paint, original helmet parts, original chin strap, decals etc? It is surprising how many new collector's never ask the most basic question before parting with their hard earned money. If you do not ask questions, the dealer can say "but you didn't ask" - and get away selling you a fake. Even an honest dealer can make mistakes, afterall he is only human and you may sense it in his presentation style, hence the guarantee is crucial.
Seller Refund Policy: Only purchase from a seller who has a 'no questions asked' refund policy.
Tip on saving money: If you are a currently serving member in the Military and purchase current military items such as Bayonets, Knives, Swords, Strobe Search Rescue Lights, Beret etc for your work, then a Registered business is required by law to issue a Tax Invoice, use this to claim back the costs on your income tax, just another useful pointer to save you money in the world of collecting.