Your Brother most likely takes a generic low shank attachment - if so, my favorite darning/free-motion foot costs $3.
It takes practice - a LOT of practice, sometimes. Not many people get up on water skis the first time they try, either. Don't give up.
Get a Dry Erase board or a scribble pad and draw/doodle a design over and over until you can draw it upside down or sideways without even thinking about it. Practice filling up the whole space with that design. When you don't even have to think about where you're going to go next, put a practice sandwich on your machine and draw with the sewing machine. If it helps, draw the design on your practice sandwich with a water-erasable marker first.
It's so much fun - jump in and go for it! :) And don't give up if it feels too difficult. The first quilts I made, my jaw would clench, my shoulders tensed up, my arms ached, I sweated and I would even hold my breath. Breathing is better. ;)