First of all it is very helpful to reply only KudoZ questions you are sure you can help with. Answering not exact information comes with a risk not be taken seriously next time. You have to remember that other translator's can comment your answer and thus fight for their own KudoZ points. There are some useful hints I added here:
1/ Follow up the questions to be informed quickly about new ones. It is useful to subscribe for KudoZ questions e-mail notifications or run KudoZ application on your computer.
2/ When you are notified of a new question read carefully all information to understand what asker wants you to help with.
3/ Once viewing the question check the time it was submitted. Sometimes it's better not to answer than answer too late.
4/ It is very appreciated by askers when your reply is prompt. So try to answer immediately you are sure about the answer.
5/ If there are some proposed answers already read them carefully and follow the links the answerers provided. Maybe you'll find out that their reply is misleading. Then your answer is more appreciated.
6/ Be sure not to provide the same answer as already submitted. The time stamp will show that you have just "copied" the answer more or less.
7/ If someone provided an answer you think is right and helpful there is still a possibility to earn some BrowniZ for the comment.
8/ Be careful with the comment and do not derogate other translators. Maybe they have studied the problem deeper than you.
9/ Always provide only answers you are sure about the meaning.
10/ Try to provide as much information as possible but needed only. Be sure the translator asking the question needs your help during his translation and has no time for your ideas.
11/ Provide only working links to support your answer. Links not showing directly the desired information are useless.
Good luck in getting points and helping other translators.