First: don't delete questions that are posted in the wrong place. If the community deems them significantly enough off-topic, they'll be voted as such and automatically moved to the appropriate place.
Now, for your answer. The best thing you can do is to read, understand, and adhere to the recommendations on the SE how to ask page. The FAQ page also has a lot of good information.
When I go to answer a question, I look for two things when determining how much effort to dedicate: first, did this person do their homework. What evidence did they give to support the fact that they're just not looking to be spoon-fed. Second, do they have an open mind. In many cases, answers given aren't exactly what the OP is hoping for. Will this person be accepting of an answer like this? If the answer to either of these is "no", then my chances of putting more then a minute or two into an answer is pretty slim.
I've looked at the tags, but it's still hard to tell what questions will get the most value.
Tags have very little to do with whether or not questions will get a good answer. Sure, they're nice for organizational purposes, but the question's content and the thought that went into it are the main things that will play into the answers' quality.