The description you have provided clearly states that your feet are excessively dry. To add to this, your feet have also got to contend with being slapped hard about a million time a day with your flip flops. When something that is excessively dry is repeatedly hit, it will definitely crack open, so your feet are not exception to this normal rule of physics and law of nature. You should begin taking care of your feet properly for them to be in good health and great condition at all times. To begin with, ditch the flip flops that are made of rubber, an extremely hard material, and opt for something softer like foam. This will not abuse your feet quite so much either. You should follow a daily routine of morning as well as night care with your feet. Each night, you should wash your feet with warm to hot water very well with soap and water and pat dry. While your feet are warm, you should apply a thick layer of cold cream to them. You can apply plain petroleum jelly to your feet. This will also have excellent results. Cover your feet with thick cotton socks and go to bed with these on. The cream will have all night to work on your feet, the cracks, fissures and the dryness. This method should take about a week to show positive results. But that is providing you follow this rule daily.
Make it a point to wear socks during the day as well, if you can. If you are in a place that is too hot or humid, you can buy thin cotton socks and wear those. If you cannot wear them all day, at least try and keep them on fro about an hour after your morning bath. The ritual after a morning bath should also be similar as the one before bedtime. You need not apply such a thick layer of cream in the mornings, however. You can also choose a non greasy moisturizer for the daytime. It is important you wear cotton socks as opposed to synthetic or nylon ones, as these will allow your skin to breathe properly. Otherwise, you may find that your feet have an unpleasant odor as well. If possible, you should also try to repeat the application of cream about two to three times a day. Try not to go out wearing slippers, as dust can add to dryness.
answered by G M