I have lots of tips and tricks that I have picked up along the way, enough to write a book! It is difficult to know which ones would be relevant... perhaps you could point me in the direction of some photos of your own and give me an idea of what equipment you have or have been thinking of getting. So I can gauge what tips might be useful to you.
If you visit my Deviant Art gallery: http://snomanda.deviantart.com/gallery/?offset=0 and go back to page 50 you can trace my first attempts at Macro right up to the present day. I started with a Canon 550D, an EFS 18-55mm lens and a set of Kenko Extension tubes, that gave me about 1:1 magnification. I added a Canon 500D Close Up lens which gave me about 1.5:1. A little later I got serious about Macro and bought an EF 100mm f/2.8 Macro lens, that, the ext tubes and 500D gave me just under 3:1. Now I am completely mental about macro I have the Canon MP-E 65mm Macro that gives 5:1!
These lens upgrades in conjunction with flash and flash diffuser upgrades have led me to where I am now. It has taken 18 months to go from piss poor to surprisingly good and my gallery plots the whole weird and wonderful journey. You can see the punctuation marks where I buy a new piece of kit or improve my diffuser, it is quite spooky.
... plus when taking a shot snowy has the steadiest hand I have ever seen. Trust me when I tell you that he shoots those photo's free-hand without the aid of a tripod. I am constantly awestruck and humbled by his stuff.