If you added up the replacement cost of all the rope on your boat, it would probably give you nightmares. So it is worth taking care of it.
When laying up, it is a good idea to take off as much rope as possible, and store it out of the weather. Traditionally, the advice was that halyards should be removed and “moused” for the winter. (Pull them through attached to a length of thinner, sacrificial cord, which can be left in place and then used to pull the halyard back up the mast and through the appropriate sheaves etc in the spring.)
The one time we did this, a very bad winter storm resulted in all the “mice” chafing through, and in the spring we were faced with the daunting task of rethreading the halyards from scratch, so we haven't risked it since. We do however routinely mouse a halyard temporarily, to take it out and check it for wear and wash it before replacing it.
And when the boat comes out of the water, we remove all the running rigging that can be replaced without climbing the mast, and take it home to get it clean and store it in the dry.
Opinions are divided on whether all this rope should be put in the washing machine. Some people argue that it causes unnecessary wear. Others believe it is the best way of getting all the salt out - and a dose of fabric conditioner also helps get rid of any kinks.
We had our previous boat for 16 years from new, and when we sold her, she still had a lot of her original “string”, and it was still in perfectly serviceable condition, which seems to suggest it had not been harmed by going through the machine (on a gentle, synthetic programme) at least once a year.
If you don't want to put your rope through the washing machine (and it's not a good idea to put the spinnaker sheets and guys in, with their spliced on stainless shackles - although a friend of ours swears by tying the shackles into a pair of socks, to protect them from battering against the drum!) a good soak in the bath will do just as well.
Take off as many blocks as you can, at the same time as taking off the rope. It's a good idea to label them all as you do so, or come the spring you may find it hard to remember which two blocks belong to the kicker and which to the downhaul. If you don't know it all like the back of your hand, it's a good idea to take some digital photographs before you take any of it off, to act as a guide when it comes to replacing it all.
By the time you've got main, genoa and spinnaker sheets, traveller string, kicker, down haul, furling line and so in a heap in the back of your car, you'll be astonished to see how much there is - and how heavy it is. You'll also be surprised how bare the boat looks without it.
And having cleared the decks, you'll probably find grubby marks where dirt has collected hidden under running rigging during the season. It's worth scrubbing those marks off now, even though you know the boat is going to get dirtier while it is ashore.
Get all that rope clean and dried, and as you coil each piece up, inspect it for wear and tear, especially where it does over sheaves and through jammers. Replace any missing rope-end whippings. Check those blocks and shackles, too.
As with everything you take off the boat, it's a good idea to rinse all the hardware to get salt out of it, and then make sure it's properly dry (a night in the airing cupboard can help) before putting it away for the winter.
Look at it all critically. Replace any worn or distorted shackles, or tired turning blocks (they will eventually turn into self-jammers, with potentially embarrassing consequences).
And if you want something to do to while away those dark winter evenings, buy a little book like Knots and Splices by Steve Judkins and Tim Davison (Fernhurst, £5.99) and teach yourself to do eye splices in braid on braid. This will save a fortune when it comes to replacing worn halyards - or shortening them to move the points of wear.