A good way to approach the table for your shot is to first look at possible safeties. This assures that you will not get so involved in thinking offense that good defense is never considered. Once you see a good safety, only then analyze the balls for an offensive attack. If you train yourself to look for good safeties, it will become automatic.
With the 8-ball in the open a failed attempt to pocket your ball will cost you the game. Go to the short rail using a very soft center-ball hit. If the object ball is frozen, the cue ball must drift to the rail after contact (or you must drive the object ball to another rail (which would be dumb.) If the object ball is not frozen, either the object or cue ball must go to the rail after contact. The key to this shot is speed. It requires a hit slightly harder than it takes to get to the object ball. If you pull it off (and you can do it easily with practice) you will hook your opponent tightly behind your ball and get ball in hand when he misses the 8-ball, or at the least a good second chance to sink your ball from a better position should he manage to hit it. Variations of this shot come up frequently. Try moving the cue straight back (toward the detail insert) to create more challenging angles off the short rail.