The longer you're in the hobby, the more intuitive this becomes. You'll develop your own flying style and interests, and those will lead you to certain airframe/engine combinations. The best thing to do is experiment and watch other flyers. In general, pay attention to the weights involved. If you read that a plane is often nose heavy, you'll want to find a lighter engine. This might mean a slightly smaller engine, where you have less weight all-over than if you'd use a heavy engine and had to add tail weight. The opposite is true for models that tend to be tail heavy.

So, in large part the answer is: "It depends." Do your research here and find out what people are using.