I guess that just depends on how long the starter has been sitting around for. You want to try to pitch that starter soon after making it. I usually let my starter go for 24-48 hours on the stirplate and then cold crash for a night. This will bring the yeast out of suspension to make it easier to decant. The next day (brewday), I'll take it out of the fridge, decant and then bring up to room temp for pitching.
If you're planning on making the starter well in advance, you may need to reactivate the yeast by feeding them some new, sterile wort, but that's only if you're keeping it in the fridge for more than a week without pitching.