Hare Krishna
Please read the conversation between Srila Prabhupada and Bernard O 'Grady:
http://www.angelfire.com/ego2/prabhupada/what_kc/best.htm
Here Srila Prabhupada says that whatever you do, do for Krishna.
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Srila Prabhupada: So when you compose music, compose music about God. That is your perfection.
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If this is currently not possible at present then the following example has been provided in bhakti.
Consider a married woman who has a lover (other than the husband, of course) whom she dearly loves. So she will do all her duties and behave with husband absolutely normally but as soon as she gets a chance she will be thinking of the lover and trying to meet him. So in the heart her only interest is the lover.
Similiarly we have to cultivate this attitude of having only Krishna as our objective by chanting, assosiating with devotees, reading etc. as much as possible. Even though we may have no real love for God, for that truly comes later, the desire to have it should be strong, for how can something be obtained without desire. My suggestion would be to also read Updeshamtra (The Nectar of Instruction) by Srila Rupa Gosvami which is available in the books section of this site.
Note that in the above example the relationship of lovers outside marraige is considered, which in its perverted form in the material world is actually only lust and in material world is considered to be most degraded; but in its original spiritual form has been considered the highest, with Krishna as the only Purusha (male) and all His energies as female. So our material conceptions cannot be applied at all in spiritual realm and devotees should not even attempt to.
Another example of an expert dancer is given. When an expert dancer with pots on her head is dancing, she makes all kinds dancing poses but all her attention (implicitly) is on the pots on the head so that they do not fall.
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So although Krishna clearly tells Arjuna about renouncing fruits of one's action, in the end He just tells Arjuna to surrender to Him completely -- which is offering everything to Krishna.
This is only in my limited understanding and knowledge which is very meagre, so other devotees can share more with us all.