Applying preventive solutions such as tape, padding or moleskin to trouble spots (based on personal experience) can help prevent blisters from appearing. You can also use friction-management patches which are applied to the inside of shoes. These will remain in place longer, throughout many changes of socks or insoles.
On the hands: Depending of what is your favourite activity, you are more or less at risk of developing hand blisters. If you are using tools or carrying out manual work, wearing gloves should prevent the majority of blisters. The same goes if you are playing a sport where you are holding a bat, racket, club etc. For some other sports such as gymnastics, weightlifting or rowing, applying tape on the hand is an effective way to prevent blister occurrence. Additionally, the use of talcum powder in order to reduce friction could prove beneficiary in combination with gloves or as a stand-alone option. Keep in mind, however, that talcum powder also absorbs moisture and as such is not a good option for prolonged activities.