When building muscle, work big body parts before small body parts.
Bigger body parts require more energy expenditure, and generally utilize tougher compound exercises. You want to make sure you work the largest muscle group of the day when you are feeling the freshest. If you work minor body parts first, you risk not being able to lift as much weight. This decrease in resistance and effort makes it harder to maximize gains because you are training at a sub-optimal level.
Work the following body parts first:
After these body parts, it’s ok to work arms, calves, abs, traps, and forearms.