Give them to other people if you are able (I.e, kill is secure, can give to anyone), and you yourself have enough to do your job. You can't be everywhere. Making your teammates stronger is how I play leblanc. You need enough to do your job. Doing 2000 damage to that ad carry when 1500 will suffice is pointless. Give the money to those who stick around. It'll make your team-mates love you as well. Most of the time.