It's tough and, ironically, it takes practice, but it can be done.

Keeping your heart rate low on hills also means you need very easy gears though, but with a mountain bike you should have what it takes.

Our coach always says that you have to ride slow to become fast....

I don't really have tricks, especially going slow, and being happy about it, not letting yourself become down because you feel soooo slllooooww.. Just smile.