Signing a striker, play Ansu Fati more often? What should Barca do to 'kill games' better?

Although Barca are generally doing much better than a year ago, one thing remains unchanged – we are still poor at 'killing' games and winning them comfortably.

Since the club season resumed in late December, Blaugrana failed to do that in 6 of their 8 games, keeping things tricky until the last minute.

In your opinion, what is the way to improve that? Maybe signing an extra striker before the January transfer window shuts would help? Or maybe Xavi should give more game time to Ansu Fati who is particularly good at scoring in second halves?