I'm afraid I have yet to see them in the UK, but if you are going to the US, I VERY highly recommend picking up a pair of Cole Haan's new range of Nike Air shoes. They are AMAZING. They look like perfectly attractive 3-inch heels but they have Nike Air technology in the soles (Cole Haan was recently bought by Nike). It is like walking around in trainers! Honestly, I cannot say enough good things about them - they are the best thing since sliced bread. You can check them out on www.colehaan.com.
Buy shoes that you can walk around in without clenching your toes to keep them on - even if your feet are at an odd angle all day, you want them to be relatively "relaxed". Anything with an ankle strap is good.
Try M & S Footglove shoes. The most comfortable pair of shoes I have ever had came from M&S. They have recently got a new range in (by an Italian designer?) they are good too.
The Party Feet rubbery insoles are good to use but are pricey at £5, I bought 2 pairs from Savers for less than that so shop around.
To feel comfortable in heels at work you have to build up a tolerance to the height of the heel. If the shoes are comfortable then you should wear them at home increasing the time while you are walking around doing the vacuming and things. Once you are used to heel your legs will respond with muscle memory and you'll forget you are wearing heels.
-Buy shoes that are the right size. If in doubt get your feet re-measured.
-Go for a medium heel height.
-Break them in.
-Try to buy all leather shoes, as they are better quality, won't cut in, and won't make your feet sweat.
- Get party feet gel cushions, and place in shoe at ball of foot, will ease the pain.
- Cheat, travel to work in trainers/comfy shoes and then change into them ( Can recommend)
- Wearing crocs at home after a day in heels -massages the feet (I find).
-Alternate days of heels and flats.
-Do a pedicure- so you don't get in growing toe-nails, rough skin build up, etc- anything that can cause friction will make it painful.