I clean everything thoroughly when I've finished using it (including giving bottles a good rinse out til there's no sign of yeast / visible dirt left) then store it until brewday / bottling day. Then after I've got the mash on I'll give everything that's going to touch the wort post-boil another quick wash in with washing up liquid, rinse off the suds and spray down with starsan. It takes remarkably little time once you've done a couple of brews and got it set into your routine.
I've seen / heard people talk about sanitising EVERYTHING, including their boil kettle, sparge water heater, mash tun etc. but I can see no point in sanitising anything pre-boil as the boil will kill off pretty much any nasties that may be present.