We have a holiday apartment but it is 400 miles away from where we live so we have to rely on our agents to do the 'turnaround' servicing etc. Due to Covid, they have had to remove a lot of things that we had previously left eg tea and coffee making supplies, olive oil for cooking, vinegar for when they have fish and chips etc. I guess this is because it would all have to be cleaned between guests (the cleaner now does a 'deep clean' between all guests). With regard to kitchen equipment, I provide items that I had rarely found in self catering properties I'd stayed in but had wished I had. Examples are an electric hand mixer, a lemon squeezer and a pvc apron. But probably the thing that most people will benefit from is a set of comprehensive notes about the flat (how the shower works, when the bin men come etc), the town (where the necessary shops are, best restaurants pubs and take aways) and local places of interest, including how to get there by public transport, if needed. There is also a drawer filled with leaflets about attractions, local and further afield. One thing I have done which people have remarked on positively in the guest book is to stick laminated postcard sized notes onto the tiles next to the oven, washer/drier, heating controls etc with quick instructions on how to use them, so that people can get started quickly without having to hunt for instruction leaflets. Good luck with your new venture.