What is a good fitness routine for a full-body workout?

The most efficient and effective way to do a full-body workout is to focus on multi-joint exercises that give you the 'most bang for your buck'. This means the more muscle groups you can work at once (within reason), the better. For example, instead of just doing a set of biceps curls, perform lunges with a curl at the bottom of each lunge. Focusing on multi-joint exercises will allow you to train all of the major muscle groups without spending your whole day in the gym.

The best time to do fitness workout thing in the morning, before you have eaten. This taps into stored body fat instead of food you have recently eaten. If you can’t walk outside or on a treadmill, you can melt pounds in place. Turn on some upbeat music and walk in place pumping your arms and bringing your knees as high as you comfortably can. Advanced: To advance the move and tone the body further, hold a soup can in each hand and “punch” one can alternately up and forward on each 4 count of steps.

There are literally thousands of exercises to choose from.
Here is an example of a total-body workout:

1. Push-ups (kneeling or regular)
2. Pull-ups (assisted or regular)
3. Standing shoulder press
4. Standing biceps curls
5. Triceps kickbacks
6. Bodyweight squats

Perform 1-2 sets and between 8-20 repetitions with a slow and controlled tempo.

As you can see, full-body routines are almost infinite in their variety. Adjust your routine to match your fitness needs and goals. If you are training for a sport, be sure to add in power, speed and agility work. The key here is to get creative with your workouts but not to the point where the exercises lose their effectiveness. Trying to create the perfect 'functional' exercise by combining as many exercises and variables as you can will only result in a loss of effectiveness and possibly an increased chance of injury.