Beejamantras

Biijamantras or Seed-Mantra-s are the "seed" sounds associated with different aspects of Universal Manifestation. A few Beejamantras associated with Devataas or Deities. Beej-mantras are also associated with Mahabhutas (Gross Elements), areas of one's body, etc. Each of these Biijamantras is the perfect sound representation of a particular deity, gross element, etc.
Beejmantras related to deities: Sarasvati (goddess of knowledge and eloquence), Durgaa (the inaccessible goddess), Ganesha (the son of Shiva who removes all obstacles), Shiva (the Supreme Auspicious Self), Bhuvaneshvari (the Mistress of the world), Krisna (the Supreme Dark Lord, guru of this universe), Kaamadeva (the god of love), Kaali (the goddess ruling over Time), Nrisimha (Man-Lion or the fourth incarnation of Lord Visnu), Mahaalaksmi (the goddess of fortune) and Shakti (in the form of the Supreme Woman ruling over the entire universe). Obviously, the repetition of a Biijamantra linked to a particular deity will develop in a person the qualities and attributes embodied by that very deity. For that reason, if you want to develop knowledge and eloquence, it would be really propitious to you to repeat the and so forth. In turn, every Biijamantra may be also used for a worshipper to offer his/her love and devotion to his/her chosen deity.
Om, Aing, Shreem, Kreem, Hleem, Nim, Nrim, KleemAll these mantra Creates a strong base for all sadhanas.
Beej Mantras are single character mantras which are as capable as any bigger mantra. Sankrit is called the language of gods because every character of Devnagari, current script for Sanskrit, is a Beej Mantra. Beej Mantras are free from all restriction; there are no rules, no rosary or yantra is required and no diksha is necessary. And best of all, these can be recited mentally anywhere while doing anything. To recite mentally, imagine to be hearing the mantra again and again in own voice.
Beej Mantras are available for each deity or god, thus have solution for any situation.One of the best example of their power is the Bhuvaneshwari Mahavidya Mantra - Hreem which is a Beej Mantra.
The method is simple. Pick a Beej Mantra of your liking or based on the situation, and recite it as much as you can till the problem is solved. You can do it in office, in gym, in restaurent and even while sleeping.