Choosing a golf putter is all about finding the right putter that fits your putting stroke. There are hundreds of putters on the market today and the choice can be overwhelming. It's important to remember that putting is about feel -- and finding a putter that appeals to you visually and one that you feel comfortable using will improve your putting game immensely.
You can spend a lot of time reading through reviews of golf putters and they will give you plenty of insight about the technology used to make a putter and how other people like using it. But until you spend some time at your local putting green with your new putter in hand, you'll never get an accurate read on the putter.
The first thing I like to do when trying out a new putter is to take three golf balls and drop them down on the putting surface. I'll start with close putts within 5 feet because I'm just getting warmed up. Take a smooth stroke and see how the putter feels. Make sure to take note of how many puts go in and how the putter is feeling at that point. When I've done about three passes at this length, it's time to move back to 10 feet. Repeat this process with a few more lengths until you've started to take some lag putts. This process will give you a really good idea of how the putter feels at all sorts of different putting lengths.
One thing you won't be able to figure out from this test is how the putter reacts on different putting greens with different green speeds. Unfortunately, there's no quick way to test this. I'd recommend keeping a few putters in the trunk of your car. There are a ton of cheap putters out there, especially on eBay, so it's easy to afford more than one. If you plan ahead, take a few minutes to test out two or three different putters on the putting green before your round if you haven't played on that course before. Notice which one feels better and suits the particular type of green you're going to be playing that day.
When evaluating a putter, there are a few things besides feel you want to look for. The first thing is lie. When you take your normal putting stance and insert the putter into your hands, the sold of the putter should lie flat on the ground. If you push your hands forward, you'll notice the heel is sticking in the air and if you pull your hands closer to your body, you'll notice the toe sticking up. If the putter isn't sitting right for you at your normal stance, you'll have a tendency to push or pull puts. Get this adjusted.
The second thing to look for is shaft length. Remember that every golfer is different. The shaft length is determined by where your hands come down naturally. Take your normal putting stance and let your arms hang down at your side relaxed. Then clap. When your hands touch together make sure to keep them there. That's where your natural putting stroke should start, and thats how long your putter shaft should be.
Remember that when choosing a putter the most important thing is to find a putter that feels natural. The more comfortable you are with your putter, the better your putting game will be. It's that simple.