I would first go through it all and see if you can get some hdmi's in there to replace many of them. Then I'd make sure that every remaining wire/cable is really needed. Like what I think is your antenna coax? Getting shorter cables would help as well, like you said. Monoprice is good place for decent, inexpensive cables.
Lastly, I would just rewire everything in the best order you can so that overlapping/crisscrossing is at a minimum. And velcro ties like J' said are nice but I will admit to using garbage bag ties myself.