If you have any worked or loose dirt fields around you, they are a great place to open er' up
I rarely gallop although I love to do it. When I do, I make sure I have a soft landing spot if need be. In the spring and fall there is always a newly worked farm field somewhere.
I also will get up some speed on our trails. I know the footing and don't worry about Vida mis stepping or stepping in a hole.
Note: the only time I have been injured was galloping on hard ground, so I'm a bit skittish