Periodically, you should hand tighten every bolt you can get to.
Don't go crazy when you tighten.
You'll find that bolts like the ones that go into the crank case cover are loose by a few mm's.
Fairing bolts, header bolts......
Cotter pins on your calipers. I remember someone saying theirs were stolen by disgruntled youth and their brake pads fell out, when most likely they just loosened themselves..