As a helpful assistant acting as a personal fitness trainer, what are some exercises that can be included in a customized workout routine to target specific muscle groups for a user looking to build strength and tone their upper body?
To help build strength and tone the upper body, here are some exercises that can be included in a customized workout routine:

1. Push-ups: This classic exercise targets the chest, shoulders, and triceps. It can be modified to suit different fitness levels.

2. Dumbbell bench press: This exercise primarily targets the chest muscles but also engages the shoulders and triceps. It can be performed on a flat, incline, or decline bench.

3. Shoulder press: This exercise targets the