Being there throughout the day for my children warms my heart. Trade the toys out at regular intervals. This can work wonders, especially if you pay them something or take them for ice cream afterwards.
Children get sick, sometimes misbehave and can cause moments of embarrassment.
Learn to smile and shrug it off. Learn to maximize your productivity in small blocks of time. Have your spouse take the kids on errands, make a few phone calls during nap time, or during their favorite cartoon. If possible, hire as much outside help as you possibly can. A cleaning service for the house, someone to do the yard and wash the windows, etc.