You might do nothing but celebrate. When we were quickly climbing the top ten did exactly that. The "snowball effect" is mostly what keeps the momentum going an

You might do nothing but celebrate. When we were quickly climbing the top ten did exactly that. The "snowball effect" is mostly what keeps the momentum going and if your app is a good one people are already recommending it and you will keep going. If that does not happen and your expectations are not met you can take it as a sign to improve the app. That being said I would keep very close attention to reviews. (I use appfigures to keep track of that) and fix very quickly everything that should not be. Even though we were #2 there were a few bugs reported via the review system and there is a lot of people that are kind enough to let you know, If you have a tool like crashalytics thats even better. Congratulations!