Can you do it? Can you pretend you’re someone else and just forget everything you know? As a designer, you have to do it often.
If you just designed a new home page, take a break. Don’t look at it for a day or two, and then set a goal for yourself to achieve and pretend you’re someone else using your design.
That’s what user testing is for, but we don’t always have the resources to do it. So, learn to think like a user and continuously test and question your own design decisions.