I am one of the last people on earth to use a daily agenda book. I am a surveyor, so the book goes everywhere with me, and takes quite a beating. So, around October of each year, out comes the duct tape. Note the digital camo pattern on the tape I managed to find.
All you need for these projects is a roll of tape and some scissors.
The damage to my dayminder is generally along the spine, but because of the tapes' aesthetics, I covered the whole thing. Cut strips to size, and firmly place them on the books cover; trim corners for proper 'lay down'.
And there you have it; a repaired, fully functional, good looking daily agenda / journal / log book.