Speaker cables first....don't bother cutting them back,simply fit(or have fitted) a decent set of banana or spade connectors,which will ensure a good,stable and reliable contact,without the risks of frayed or loose wires knocking around....also makes any disconnecting for resiting etc much easier.
By all means unplug and replug interconnects to maintain the contact surfaces,or you can also use things like Kontak,which although not cheap,lasts for ages,and will lift the rubbish from plugs and connections of all kinds very effectively.
http://www.britishaudio.co.uk/kontak.htm
Thats what mine gets every now and then,and removes a surprising amount of dirt.