You are in the windmills forum. And practice would help you with your handstands. If you fall back onto your feet, it means you're too scared to risk falling down onto your back. It's good to take a video of your handstands, because if you're doing something wrong, it's very obvious.
Not always, President... after the first periods it's very hard to catch what makes you fall forward or backward just from a vid, it becomes even more important to FEEL what you're doing and to pay attention to it. Anyways depends on what level you're at, depending on how your tries are you may need to try them against a wall or you may need the more advanced tips.