1. Have a goal
There is no point in putting in a bunch of effort with no clear direction of where you're going. Decide what your fitness goals is and plan out the steps to it.
2. Make a nutrition plan. Your diet/what you eat is the biggest key to any fitness goal. If you don't have this on point everything else will fall short.
3. Hydrate and sleep Giving your body enough time to rest and recover is even more important than the workouts themselves.
4. Full-body workouts Since most of us will not have access to a full gym you have to make the most of what you have.
5. Core & calf exercises daily
You core and calf muscles will recover very quickly compared to other parts of your body likes legs and shoulders. So it is not a bad idea to train them daily.