The weakest link in a shooting system is your scope mount. The finest rifle and scope combination is rendered useless without rugged and reliable rings and bases. Often, a problem is not foreseen and results in a miss, or even worse, a wounded animal. Countless rounds have been wasted due to the improper installation of rings and bases, and the frustration that results from missed easy targets takes the fun out of informal plinking and target shooting.
Poor base and ring installation may result in more than bad accuracy. It can destroy scopes and damage rifle receivers and bolts, and can even be dangerous to the shooter. Having a gunsmith install these critical links between your gun and scope is always a good idea, and the peace of mind from a professional installation is well worth the small fee. Do-it-yourselfers often end up spending the saved money anyway on ammo in a fruitless and expensive effort sighting in. This aggravating process is more like work than pleasure. Remember, shooting is supposed to be an enjoyable activity.
An ideal mounting system secures your optical device to your firearm as low as comfortably possible, with the fewest parts necessary. More parts equal more chances for something to go wrong. Solid steel mounts are the strongest, but in many cases, aluminum will serve perfectly well. See through rings are notoriously weak, and points of impact change from bumps or carrying are common. With a good scope with low enough minimum magnification; your iron sights will never be used.