Back in the early eighties I met an older gentleman bow fishing on the Deepfork river here in Oklahoma , he was using a bow he had made and a wood arrow with what looked like a field point with small nail barbs braised on it , he did not have anything on his bow to hold the line but instead he held the ends of loops between his fingers so that when he made a shot the line would slip out from between them .
His shots were about fifteen feet at the most because that's all the line he had ( he had a loop on one end that he would run his belt through , he also would push a stick into the mud and put the loop over it ) , when he got a fish he would just run the arrow on through and pull the line through .
I use this same method sometimes and it works if your shots are close , be sure the loops between your fingers are barely tucked in .
I had pics of how I hold the line but must have delited them .