Dips exercise:

How to do dips

This exercise too doesn't require any special equipments other then bar and like push-ups is a good compound exercise.It works mainly on lower chest (not the upper or all).

If possible use a wide grip "V" bar for working chest. If a V bar is not available, parallel bars are fine. Dips are a good alternative to decline press and because of the stretch involved, also works the outer upper area of the pectorals.
If you lean back (you can't too much), you work your triceps so, For maximum pectorals workout, try to lean forward (just a little).
Again don't lock the elbow joint. I hope everyone knows how to do them correctly .
Go all the way down to get the maximum stretch.

This exercise builds strength and mass in the entire pectoral muscles as well as working the front deltoid.
Start with your arms extended and slowly lower yourself as far down as you can go.
The farther forward you lean the more you use your chest, so try bending your legs and crossing them at the ankles behind you.
Squeeze the pectorals at the top of the movement ensuring you're working them as hard as possible.