If your goal is to create a great workout using body weight movements than what you need to do is observe athletes that use body weight movements to create incredible bodies.
Your body is a highly adaptable machine and needs lots of variations to keep improving.
Athletes such as dancers, gymnasts, and yogis (people who practice yoga) don't perform "workouts" the way the average person does.
Instead, they design routines where they perform a series of exercises that "flow" well together.
So, why not use the same concept to design your own 30-minute workout? Here's what you do: choose a handful of body weight exercises that flow well together, set the timer for 30 minutes, and try to move through the routine as many times as possible within the time period.
What do I mean by "flow'? Well most people will do a set of pushups, followed by a set of squats, and finished off with a set of pullups.
But they'll do them in sets and reps.
How about standing underneath a pullup bar and performing 2 pushups, 3 squats, and 1 pullup.
That's just a basic example of creating a workout that flows.
In reality what you should be doing is more complicated stuff.
For example, try performing a pushup, followed by a forward roll.
Stand up into a squat, then do a squat jump.
That's one repetition.
Now reverse the direction.
Squat down, roll back, and perform a pushup.
That is the kind of "flow" I'm talking about.
But you can incorporate other exercises and take this as far as you'd like.