I like to do my starter about 10-14 days ahead of brew day so that I can cold crash the yeast down to the bottom, siphon off the 'icky' starter beer, add my fresh lager wort to resuspend the yeast, and then pitch. I like the extra lead time because if something isn't going right I have time to fix it too.
I call the starter beer icky because I actually tried bottling it, letting it CO2 carb up like a proper beer and drinking it -- yes thats right totally unhopped yeast starter from DME. It wasn't the worst beer I ever tasted, and it was far better than I thought it would be, but it still earns 'icky' and so I avoid adding any more of that starter beer to my carefully brewed lagers than I must.