You know your customers or least the ones who are in your shop regularly. You know which brands they're loyal to, and the handguns they've already purchased. The next time one of these customers comes in, place in their hands "their next handgun."
Let's say you have a customer who loves his full-size Smith & Wesson .45 semi-auto. You'll be doing him a favor to sell him the blue Model 457 or stainless equivalent from Smith's economy line. Both are best-buy lightweights that are easy to hide and comfortable to carry in concealment holsters, yet they hold only one round less of .45 ACP and work identically to their big brothers.
Do cops come in wearing their full-size P220 SIG .45 duty gun? They're naturals for the compact, lightweight SIG P245 in the same caliber. There's even the all-steel, but easier shooting stainless P220 ST for recreational or competition shooting.
Then there's the customer who is delighted with her tiny, super-light Kahr PM9 9mm pocket semi-auto she bought for...