I get kind of crazy about high-quality hardneck garlic at the farmer's market. It has a strong, rich flavor, and a thick, oily texture that I find entirely different from normal garlic. Our local Whole Foods usually only has extra-gross garlic with that odd baloney smell old garlic often gets. To be able to taste quality garlic in the off season, I decided to start making my own garlic extract (which also makes cooking a lot more convenient).
First, while this picture isn't great, you can see the difference in how much garlic oil there is between the good garlic (at left) and the normal garlic (at right):
Anyway, to capture that goodness, just chop up a ton of good garlic, and let it soak in some decent vodka. No need for top-shelf, but please don't use gross super-cheap vodka which has off flavors. Svedka has the best quality: price ratio in my opinion, so it's what I used. Here's the vodka soaking up the garlic flavor:
After it tastes sufficiently garlicky (I gave it 2 days in the fridge), strain through a cheesecloth. Now you can just add a splash of it to your stir fry, and it will taste like fresh garlic! Wayyy better that garlic powder.