Set out all of the ingredients beforehand, and put them away after using them - that way, you can quickly put the dish together and not leave anything out.
Timesaving appliances are also great helps - the food processor, blender, mixer, auto bread machine, etc.
Chop ingredients ahead, i.e., if you use a lot of chopped onions, chop several, package them in recipe-size bags, and freeze or refrigerate them until needed.
Also modules (several found on the Quick Cooking Site) are HUGE time savers. Much of the prep is already done.
There are dozens of hints on the Quick Cooking Site!