As I near the end of my PhD, I would add the following advice. Don't undervalue your creative time or your sleep. By creative time, I mean hiking, dog walking, making a bird house, etc. Make time for our mind to wander.
My research direction became clear to me while I was daydreaming on a family vacation. Subsequent dog walks have set me up for a good five years of material. As far as advisors go, I quote Arthur C Clarke: When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
Thanks for the advice!! It never fails to astound me how clearly you're able to think when you're not putting any pressure on yourself to think clearly :). And that quote is awesome! I just realized my advisors are actually pretty diverse age-wise. My primary advisor is early-mid career (got tenure a couple years ago), one of my secondary advisors is a brand new assistant prof, and my other secondary advisor is close to retirement.