I agree with Red Vision, we should bring back the banners and maybe those decorative capes like in rs3 to attract more people so that they can get into the concept of clanning.
Also, I think that clan wars and fog should be moved back to the wilderness like it was in 2011 when clanning was at a peak. I believe that the "Safe Spots" in the wilderness is what attracted a lot of people into actually going into the wilderness.