In both areas the same attention needs to be given to damp, security and bugs.
Check for and fix any rain water leaks which will degrade cabin furniture and get into your electronics, causing mould and mildew if the yacht is not properly ventilated when it is laid up. Wiping cabin linings with a weak solution of water and vinegar can help prevent mildew.
Bugs and vermin just love to squat on your yacht if they can find a way in, so check the security of your covers and hatches and make sure that they can’t get onboard via securing straps or mooring lines. Skin fittings should be taped up to prevent entry
Check every compartment before and after laying up and make sure you have removed any food.
And don’t forget to treat your diesel tanks with biocide if you are going to leave the yacht laid up for some time – diesel “bugs” can cause great problems with blocked filters and injector pumps
Don’t leave valuable portable items on the unattended yacht. It is amazing how many high value outboards are left poorly secured for all to see. Best take it off, get it serviced ready for next season, but keep it and anything else valuable secured under lock and key even when at home.