The Red Dragon on the bridge going to the Tower Knight is easy to kill. Get a crossbow and 100 bolts. Go to the top of the first tower on the bridge. Kill the two archers. You will see three archer windows. Go to the one on the far right. This may require about 20 to 30 minutes but it is worth it. Lock on to the dragon every time he swoops down to burn the bridge. You will eventually kill him and get about 8,000 souls and his lead soul.