Here some tips that I've found helpful in helping sculpt my upper body.
You may have benched 250 pounds back in the day, but it’s important that you shape your workout to fit your fitness level right now. Don’t hoist more weight than your joints are ready to lift. Start low and work up to heavier weights gradually. Different muscle groups will require different amounts of weight.
Choose a weight that is heavy enough to challenge your target muscles, but not so heavy that your joints feel strained. Start with dumbbells that are at least 8 to 10 pounds and gradually work up to using 10 to 20 pounds or more, depending on the exercise.
If you are new to lifting weights, or have not done so for six months or longer, then build a base level of strength for eight to 12 weeks by doing one to two sets of eight to 12 reps of each exercise, two to three days per week. Rest for two to three minutes in between each set of each exercise.
Once you have a base level of strength, perform two to three sets of eight to 12 repetitions of each exercise. Rest for one to two minutes in between each set of reps. Do this workout two to three times a week with a rest day in between.