It depends on the ages of your kids, and the flexibility of your work schedule. I usually stop work when the kids get home from school and then either work after bedtime for another few hours or get up super early to put in a few hours before the household is awake again. Depending on the kids' schoolwork, sometimes I work as they do their homework...if they don't need too much help. It was actually easier when the kids were a little younger. They could play for a good hour by themselves after a nice snack. Then I'd prep dinner as they did their homework. I seem to have less time now that there is more homework to manage..and more activities to drive to.
We did aftercare when we had meetings during after school hours, or if we had big project deadlines and really had to concentrate. The kids were there once a week or so. They loved it.
My kids also learned fairly quickly to stay quiet when I am on a phone call. When they were smaller, I would let them watch a quick show only when I had to take a business call. They were super quiet. ;)
I've never had a problem working at home with them. When they were 7 and 9 we started keeping them home with us all summer. They play and do their daily "mom" homework as we work. They love it and so do we. When they were younger, we had a summer nanny and camps to fill the time. Now they are thrilled to have time at home to play with the neighbors and just chill in the summer. It's always a balancing act, since they want us to play and do fun things, but it's so great to be with them.
A routine really helps to keep up with household work and regular work. When you work at home, they tend to blend. I would much rather work than do laundry and dishes, so it's not a huge issue, but I have to force myself to throw a load in and keep up with the kitchen. Since we're here all day, it doesn't stay clean.
I also get ready for work each morning as if I'm heading out to work. Shower/dress so you feel focused and ready for the day. When I don't do this, my attitude and work suffers.
Honestly, I was more distracted by coworkers at my old job, than I am with my kids at home. I get a ton more actual work done at home. Less meetings, less pop-ins and more work.
It is stressful though. It's hard to manage other people's expectations, since you are home and they don't understand you are working full-time. Family and friends like to schedule things during the day and it takes a while to convince them that you are really working. I also think I am in-between being a stay at home mom and a working mom, so you have double the responsibility. I try to volunteer at school, do the activity driving, do the after school routine, do nice dinners and household upkeep. It's exhausting. There's a lot of pressure, since you feel like you should be able to do it all...since you are home. Let me tell you right now, cut corners where you can and take your expectations down a notch. If you are working from home, you are still working. My husband has to remind me often that I am trying to do too much.