Well, what most people do is use a tiling texture. The texture is small, but can be repeated over a large are without noticing the seems of the texture.
What i have started doing when i'm unwrapping is to find parts of the model, that can be repeated. Such as a human model. You could use the same part of the texture for both arms.
What i have started doing when i'm unwrapping is to find parts of the model, that can be repeated. Such as a human model. You could use the same part of the texture for both arms.