Always think the best not the worst of each other - recognise that everyone is working hard to make it work, even if you feel it is only you that is holding it all togetehr.
Men are not incapable of sorting out clothes/school bags/laundry/packed lunches!
Make time for one on one time with all members of the family each week (including your spouse)!
If you are doing stuff for school make sure you do the big bang stuff that buys lots of school credits to keep in the bank for the times when work is so hectic that you can't man a stall at the Christmas fair/can#t attend the christmas fair at all/can't attend christmas!
Take lots of photographs of everyday things, and encourange the people looking after your children to do so too. When you've bust a gut getting to the school concert/sports day you might not be in the mood to enjoy it but by the time you have the photos in your hand only the positive memories remain (within reason)!
If you are senior enough, never try to explain your absence to your staff - you are just 'unavailable' for the afternoon. But don't then take the photos from the above para into work to show off! In fact don't take any photos into work - they aren't really intersted in them and it will only open up endless hours of having to gaze adoringly with extreme boredom at everyone elses children/dogs/horses.
Most large corporations use outsourcing for a good reason - emulate their forward thinking in the home (although admittedly some companies are shit at this - so only copy the good ones)! Get whatever support you can afford in the home - remember there are 50 shit weeks in teh year if you don't have a cleaner - are you sure that 2 weeks in the sun is worth 50 shit weeks!
Be clear about why you work - this helps with the guilty feelings.
Don't worry about feeling guilty if you are a WOTHP - loads of us feel guilty at least for some of the time. Just think of it as joining an elite gang of guilt monsters