Living in Dallas, Texas makes carrying concealed very challenging at times.
In the winter months I ususally tote my Smith & Wesson .41 Magnum snubby in a Sam Andrews horizontal shoulder rig with three spare speedloaders on the offside carried horizontally. As a backup I'll stuff my Smith & Wesson 640 Centennial or Kahr K-40 in my overcoat pocket as a backup.
When it warms up a bit, I'll carry the same setup with a light Members Only jacket. As a sidenote, if you like shoulder rigs and live in a warmer climate, try buying a Members Only jacket one size larger than you normally wear. The cut bellows the sides out to make concealing even my chunky N-frame a piece of cake and they're lightweight as hell.
In the summer months my Colt Lightweight Commander rides IWB either with a Clipdraw apparatus mounted under the grips or in a Bianchi Bellyband underneath an untucked shirt. If something more formal is called for, my Smith & Wesson 640 Centennial or Kahr K-40 rides along in my strongside pants pocket in a Mitch Rosen Pocket Softy.