Should one avoid answering any specific questions?
Well, starting to answer questions which are bound to get closed is generally a bad idea as you can end up typing a good answer which you then can't post - although if you think you can get an answer in quickly and you think the question won't actually be deleted, that means it's more likely to end up being accepted (you get less competition). I don't actually think about things like that when answering, but in hindsight it makes some sense.
Fundamentally, just try to be helpful. The more helpful you are, the more votes you're likely to receive. By the time you hit the rep cap regularly you could start trying to optimize for accepted answers instead of votes, but it's not really a good idea. If you're doing it for the reputation rather than to be helpful, you're missing the point anyway.
A while ago I wrote a blog post on answering technical questions helpfully which you may find useful - but it's aimed to helping, not at reputation.