If you think you need the boards to slow down, you needed them earlier. If you think you need the gear to slow down, drop the gear NOW. If you know you need the gear to slow down, get ready for a go-around.

The 737, 757 and 767 as well as the A320 series do not slow down as well as the DC-9/MD-80 or the 727. In the -80 and the 727, you can throw away a lot of energy fairly easily.

So, on the Boeings, drop the gear, pull the nose UP and get lots of flaps out. Less than 15deg and you are not getting lots of drag. Greater than 15deg and the drag rise is noticeable.