I used to HATE giving blow jobs. It used to take a lot convincing from my current boyfriend to get me to go down on him. The biggest tip I can give you is to actually like the person you're going to give it to. Originally, with other guys, I hated doing it because I wasn't that into them and it was like pulling teeth for them to get me to do it. I did not at all enjoy it and then avoided the topic at all costs.
However, after dating my current boyfriend for a while, that "hated" topic came up. He told me that he'd rather have someone well-trained than fumbling. He took me through each individual step, from the hand motions to the way I should twirl my tongue.
Now, I really LOVE giving blow jobs. It is best when I know that he really enjoys it. PLUS, I get to be more inventive as time goes on, i.e. stimulating the perineum, etc.