Okay well since nobody is giving any serious answers I might aswell tell you a technique I have learnt from Swamiji Sivananda a great Yogi and Guru!
Keep in mind that this may take some time to develop, you must cultivate some patience or you will not find much benefit from these exercises.
Ajna Chakra is situated within the Sushumna Nadi and its corresponding centre in the
physical body is at the space between the two eye-brows. This is known as Trikuti. The presiding
deity, Paramasiva (Shambhu), is in the form of Hamsa. There is Goddess Hakini (Sakti}. Pranava
xdvng (Om) is the Bijakshara for this Chakra. This is the seat of the mind. There are two petals
(Yoga Nadis) on each side of the lotus (Chakra) and the vibrations of these Nadis are represented by
the Sanskrit letters:—xdvng (Ham) and (Ksham). This is the Granthi Sthana (Rudra Granthi). The
Chakra is of pure white colour or like that of the fullmoon (on the Purnima day). Bindu, Nada and
Sakti are in this Chakra. This Chakra corresponds to Tapo-Loka. The corresponding centre in the
physical body is at the Cavernous Plexus.

He who concentrates at this centre destroys all the Karmas of the past lives. The benefits that
are derived by meditation on this Chakra cannot be described in words. The practitioner becomes a
Jivanmukta (liberated man while living). He acquires all the 8 major and 32 minor Siddhis. All
Yogis and Jnanis too concentrate to this centre on the Bijakshara, Pranava!(OM). This is called
Bhrumadya Drishti (gaze at the space between the two eye-brows). More details of this important
Chakra will be given in the subsequent lessons.
Also vocalising the mantra iiiiiiiiiiiiiii works very well, pronounced like the e in Sheet, coupled with concentration in the middle brow area where this wonderful chakra resides will start to awaken it. Vocalising this mantra for about an hour a day will do alot.