The Owls were made to pay for their profligacy when Miguel Llera put through his own net to condemn them to their 10th league defeat of the season.
"I'm starting to sound like a broken record, but what more do we have to do?" said Jones. "We've created plenty of chances, we've had them pinned back, but if we don't score the goals, we don't win the games."
Jones added: "It's that finishing touch, that composure in the final third and we will continue the search to bring someone else in."
"We have been beaten by a Nottingham Forest side that has aspirations for the Premiership but we have matched them and played well, but we're missing the edge and composure in front of goal. It doesn't matter what formation we play, we will create chances.
"They are a great bunch of lads, they work so hard, and they are very frustrated in the dressing room right now because they know that we are not that far away."