A lot depends on what kind of skin and hair you have.
I am lucky in that I have fairly good skin which looks OK as long as I maintain a basic routine. That means that I can get away without wearing makeup as long as I'm not actually going anywhere. And when I do go into the office or something, I usually just rub a bit of foundation into my skin, brush some powder over the top to take off any shine, and put a bit of mascara on. Obviously if you have any major skin issues such as acne, you may feel that a longer makeup routine is necessary. But I think for most people, as long as you cleanse and moisturise each day, going without or with minimal makeup is fine. I only ever spend a long time on my makeup if I'm going to a wedding or somewhere.
Hair-wise, mine is thick and wavy, and I've found that by blow drying it and using minimal products, I can easily go three days between washes, especially if the third day is one where I'm just working from home or something. So say I wash and blow dry my hair on Monday morning, it's fine through Monday, Tuesday and usually Wednesday too. Dry shampoo is great for getting an extra day out of it. I use a very gentle shampoo and conditioner without any silicone in it. This means that it gets clean without stripping out all the natural oils, and moisturised without putting loads of gunk back in which will make it get greasy again quickly. Faith in Nature is a great brand with no nasties in it. When I wash my hair I really massage my scalp thoroughly to get all the dirt and dead skin off, and make sure I properly wash all the shampoo and conditioner out. I don't use any products at all when I blow dry it. I find this minimal routine and being strict about not washing it more than every other day, ideally every three days, helps cut down on how often I need to wash, dry and style it, which is what takes the most time, as well as keeping my hair and scalp in better condition.
That was quite long winded, but what I mean to say is that when it comes to hair and skin, often I find that having a very basic routine and not doing more than necessary is good both in terms of your skin and hair health, and in terms of your routine not being too time consuming. Low maintenance.
The other thing I forgot to mention is take a decent multivitamin. Prenatal ones are good. They help keep you healthy inside but also improve your skin, hair and nails.