My latest primal endurance fatloss workout includes swinging planks and pistons in their most basic form but if these 2 exercises feel too easy for you then you can progress to the more advanced versions and work at a much higher intensity.
In the video below you can watch two advanced versions of the piston press and then how to combine the full piston press with the advanced version of swinging plank. At the end of the video he also goes into progressions using the parallets.
Remember that getting results from your plan is all about starting at the right level and progressing from there. This is one of my favorite things about bodyweight workouts. There are endless progression and modifications so no matter what fitness level you are you can still get killer workouts that get you the results you're after.
Below are two workouts that include the swinging plank and piston press (click links for full workouts instructions).
Notice how I modified these exercises to my level. Remember that you can always modify any exercise to your needs.