Ichigo, it doesn't look too bad so you are on the right track.
Prune for a style, then use the clip and grow method, it works great for these. Don't overwater with the soil you have, and you should be ok.
Also if you are looking for growth, the bonsai pot isn't the best place for it, also watch during the heat, small pots can dry faster than you would like. I have a tendency to put these in a somewhat larger pot than normal, if for no other reason the roots can grow quickly and fill a small pot.