L- Sit Hold, Lying Leg Raises, Hanging Leg Raises
In order to create the most effective type of workout using these bodyweight exercises make sure you don’t do all of these exercises on the same day or on consecutive days. Try to split your workouts in to 3 or 4 sessions per week.
One way you can divide your workouts is by doing upper body focused exercises one day and follow it up with a lower body and core intensive workout the following day, rest for one day and do another upper body day followed by a lower body and core workout the day after that.
You can easily choose 2 exercises per muscle group in order to get the most out of your workouts and avoid overtraining.
For sets I recommend anywhere between 3 and 4. The number of sets can be in the range of 6 and 10 if you want to gain muscle. If you find it difficult to do this many reps simply try to do as many as possible per set. Over time you will be able to do more as your strength increases.
Getting a body that is lean does not require using weights. You learn how to get a gymnast body very easily by training properly and with the right exercises.