The most obvious giveaway is the price. A fake Scotty Cameron putter will usually be much cheaper than a genuine one. Also, be sure to inspect the putter head closely for any irregularities or damage. If there are any noticeable flaws, it may be a sign that the putter is a fake. Finally, test the putter out in practice before you buy it – if it feels noticeably different in weight or feels cheap, it's probably not a real Scotty Cameron product.