Have enough Memory Cards
This one might seem obvious but it pays to have enough memory cards on a shoot. Having multiple memory cards means you can shoot at maximum resolution for your camera. Often when heading out on a shoot you don`t know how the day will pan out. Don`t get caught out if the conditions are great by running out of cards. This has happenned a few times on my workshops with guests. Memory cards are much less expensive than a few years ago.
There is a solution, the images can be backed up on to a portable storage device, these I do use especially on long location travel shoots when its not practical to have a computer with you. However I still always make sure I have enough memory cards for shoots.