Decide on the exact plament of your back tattoos. Will it be on your upper back, lower back or whole back. This will enable you to decide on the shape and style of the design that you will go for as you can make it symmetrical to the body area that you will go for. If its on your upper or lower back, you can go from small to medium tats. If you want intricate and detailed designs with lots of elements, you might want to go for a full back design.
Choose a design that has meaning to you. Do you have a believe or philosophy in life that you live by? Maybe you can express it through quotes which will look great on any part of your back as script tattoos. Or you can represent it through symbols. Have you been through at tough time in your life and you just want to be strong and move in. Why not go for koi fish, lotus or cherry blossoms? These symbols have very meaningful connotations attached to them. You can also show your personality through the elements associated with your zodia signs or you might want to honor a loved one who passed away. Tattoo imagery such as angels, cross or flowers can be fitting for this type of theme.