In this video i go through my process of creating the low poly! Starting out from a decimated model will get you the outmost accurary and speed you need to make your low poly models.
By using hotkeys and few scripts you can also speed up the process. I do not like jumping between softwares, anytime i can make a new hotkey script, or bind an existing command to a hotkey it always helps speed things up.
The only reason why you should be concerned with speed, is not for bragging rock star rights. Is simply so you can iterate. Quality over speed, always!