Coaching for set pieces

I'm not going to start a big rant about Harry. The fact is we played really well in over 20 games, and only badly in a few. One area we really fell down in was attacking set pieces, especially corners. Citeh basically won the league thanks to a corner headed in by Kompany against United and Dzeko's injury time lifeline. I think that was thier 15th from a corner in the league.
Last week we had 19 corners against Villa, and never really threatened. Don't give me Richard Dunne, we hardly threatened all season from an abundance of corners, and our free kicks seemed random. Walkers goal against Blackburn was a case of you have a go, we haven't scored one in months.
we have supposedly world class technicians like Modric and Van der Vaart, and big players in Kaboul, Dawson, King, Ade, Bale, and Sandro. I think our coaching staff are wanting, in this area if no other. We should have had about ten goals from corners, I'd say it was three or four. Needs sorting, we would have sailed into third with a better set piece threat.