When the devotee grows in devotion there is absolute self-forgetfulness. This is called Bhava. Bhava establishes a true relationship between the devotee and the Lord. Bhava then grows into Maha-Bhava wherein the devotee lives, moves and has his being in the Lord. This is Parama-Prema, the consummation of love or Supreme Love.
There are five kinds of Bhava in Bhakti. They are Shanta, Dasya, Sakhya, Vatsalya and Madhurya Bhavas. These Bhavas or feelings are natural to human beings and so these are easy to practice. Practice whichever Bhava suits your temperament.
In Shanta Bhava, the devotee is Shanta or peaceful. He does not jump and dance. He is not highly emotional. His heart is filled with love and joy. Bhishma was a Shanta Bhakta.
Sri Hanuman was a Dasya Bhakta. He had Dasya Bhava, servant attitude. He served Lord Rama whole-heartedly. He pleased his Master in all possible ways. He found joy and bliss in the service of his Master.
In Sakhya Bhava, God is a friend of the devotee. Arjuna had this Bhava towards Lord Krishna. The devotee moves with the Lord on equal terms. Arjuna and Krishna used to sit, eat, talk and walk together as intimate friends.
In Vatsalya Bhava, the devotee looks upon God as his child. Yasoda had this Bhava with Lord Krishna. There is no fear in this Bhava, because God is your pet child. The devotee serves, feeds, and looks upon God as a mother does in the case of her child.
The last is Madhurya Bhava or Kanta Bhava. This is the highest form of Bhakti. The devotee regards the Lord as his Lover. This was the relation between Radha and Krishna. This is Atma-Samarpana. The lover and the beloved become one. The devotee and God feel one with each other and still maintain a separateness in order to enjoy the bliss of the play of love between them. This is oneness in separation and separation in oneness. Lord Gauranga, Jayadeva, Mira and Andal had this Bhava.
A Caution: Madhurya Bhava is absolutely different from conjugality of earthly experience. One should not be mistaken for the other. Earthly conjugality is purely selfish and is undertaken only because it gives pleasure to one's own self. But in love for God it is because it gives pleasure to God and not for the sake of the devotee. Divine love is not selfish. It is born of sattva. But earthly lust is born of rajas and attachment to bodies. Earthly conjugality is the outcome of egoisitc self-regarding egoistic feeling, while divine communion is the outcome of other-regarding feeling devoid of egoism. Strong selfishness is the root of worldly passion; divine love is the product of loss of egoism. This is the greatest difference between lust (kama) and divine love (prema). The two are related as darkness is related to light. No development of earthly affection, however perfect it may be, can lead one to supreme joy of divine communion. Lust lurks in the heart due to the passion that burns in the core of things. Divine love is unknown to the man of the world, however religious he may be. The secret of divine love cannot be understood, and should not be tried to be understood, so long as man is only a man and woman only a woman. The austere transformation of the human into the divine is the beginning of true love for God.