Honestly, I'm surprised by how balance my life seems to be right now. Before we had Evan, I really didn't know how it would work. One issue was that I didn't even have a permanent job - I didn't know what I was going to do once my maternity leave was over, let alone how I was going to do it.
However, a couple months before Evan arrived, I was told there was a good chance there would be a job waiting for me when I wanted to return. Though this took months to sort out, it made staying at home with Evan easier knowing I had something to go back too.
Before I starting working again, I was not very happy. I know now, after being home for 9 months with Evan, that I am just not cut out to be a stay-at-home-mom (disclaimer: this is by no means a jab at any woman who chooses to do so). While at home, I didn't feel my life was balanced, as my life was solely about Evan.
Once I went back to work, I was less stressed and definitely happier. DH and I both had our work and we took care of Evan and the house pretty much 50/50. I've blogged about how we split up our duties before, so I won't go over the details again.
I think there are two major things that DH and I do that allow us to have a fairly balanced life:
1. We both have made the conscience decision that family is first and career is second. This may mean we won't be rock stars in our fields, but neither of us value that too much anyway. We both work steady hours (DH 8:30-5, me 9-4:30), and very rarely work in the evenings or on weekends. Both our jobs are flexible so one of us can be home with Evan if he's sick or otherwise can't be at daycare. We absolutely "cash in" all our vacation time without a second thought.
2. We are equal partners. As Cloud mentioned in her post, I chose my partner wisely. We are definitely partners in parenting, chores, etc.. I could not be with a man who considers looking after their kid(s) as "babysitting", or thought cooking and cleaning were women's work, or who was otherwise an irresponsible, lazy schmuck. Not only that, I found someone who has the same values and wants out of life as I do, which makes things infinitely easier when it comes to making decisions big and small.
There are other things that allow us to live a balanced lifestyle as well. We live in a city with a reasonable cost of living so we can own a 4-bedroom house in a wonderful neighborhood. The only debt we hold is our mortgage and car payments (and our debt load is not a significant fraction of our take-home salaries). This allows us to save up money quickly to invest, do renovations, travel, or make large purchases. It also allows us to "buy" time by having cleaners come to our house twice a month.
All these things allow us to live a relatively balanced life. There are things we are working on - like getting more time for ourselves as a couple and individually - but those are coming with time and effort.
This is what has worked for us, and we're both fulfilled on the career and family side of things. It can be done!