A tattoo sleeve is not for a person who casually gets a small tattoo on an ankle -- it is for a serious tattoo lover and should be thought out carefully. The most eye-catching pieces of a sleeve have significance to the wearer. But, if you want a full sleeve, you must fill in the gaps. The key is incorporating your personality while blending your tattoos together. However, you must like the filler tattoos as much as your current tattoos.
You can make clouds fit the tattoos you already have on your arm. If your tattoos have a darker tone to them, go for dark, stormy clouds. If your tattoos are lighter, go for big, fluffy clouds. Clouds work really well if some of your tattoos include birds, angels or flying mythological creatures like dragons or griffons.
Putting fingers of flames between your tattoos is another great way to fill in the gaps. This may not work as well if your tattoos are mostly drawings, such as butterflies or hibiscus flowers. Then again, it all depends on your taste and personality. You can use the fire as a symbol -- fire cleanses or fire destroys. Go with what you feel is right.
You can use the element of water and make waves, raindrops or ripples between your individual tattoos. If you have tattoos of underwater life, such as fish or an octopus, this works wonderfully. You can also throw in some coral reefs to give it a tropical look, which works well if you have a tattoo of a ship. If you have a ship tattoo, you can combine water and clouds to give your arm a wordly look.
Think of this as a family tree type, except the spots where your relatives are placed, which is like a personality vine. Vines work great if your tattoos are mismatched because each branch of the vine is a branch of your personality leading to the fruit. You can even throw in little flowers or fruits if you want something more than green vines tattooed on your arm.