Brandy
The Brandy is a Roundoff without hands.
01 Gymnast Cart
The first progression for this trick is a gymnast style cartwheel. It has 180 degrees of rotation, so you end up facing the way you came from.
02 Roundoff
Now turn that cartwheel into a Roundoff. Push off the ground with both hands as you swing both legs down. Spot the floor throughout and drive both feet down into that spot.
03 Aerial (gymnast)
The goal is to do a Roundoff without hands so you'll need to be able to do a cartwheel without hands. The one you need is the gymnast style Aerial which has 180 degrees of rotation.
04 1-Hand Roundoff
This step is easier than the previous one but is closer to a brandy. Do a roundoff but leave the second hand away. Just swing both legs up and around while you spot the floor.
05 Faster
Practice the one handed Roundoff until you can do it fast. The faster you are the less weight is placed on the hand. Swing your backleg up fast, as you would do for an Aerial. When both feet meet in the air, push off the ground and swing them down.
06 Jumping
Now you need to add a jump to the one handed Roundoff. Slightly bend your jumping knee before you enter the trick and try to leave the floor with your feet first before the hand touches down. Practice this a lot and try to place your hand down later and later.
07 Brandy
To change it into a Brandy all you need to do is replace your hand with your feet. It sounds easier than done but that is actually what you want to do. When you're performing a Roundoff, you are spotting the ground the whole time. To land the Brandy you need to concentrate on that specific spot and think hard about driving your feet there. You can use your (now free) hand to punch back behind you, to get some lift.
Tips
If you can't leave your hand away, you need to focus hard on driving your foot down into the spot where are looking. Try to be fast. Practice the one handed roundoff until you can do it really fast. Then add a jump. Swing your backleg up high before you leave the ground to reduce the distance you need to travel.
If you land on your knees or you are falling forward after landing, you may be traveling too much. Try to direct most of your momentum upwards instead of forward. Swing the backleg up really hard and avoid taking big runs into this trick for now. Just take a few steps into it and block upwards.