Since the question is generalized about documentation to show "intent to return home" for visitor visa purposes. I will list down a number of 'ties' which can be used to show this intent. All of these are based on my personal experience of mine and friends' visa applications. Details for some visa for a specific country may vary.
1_ The most basic and first proof can be your home. If you own a house, apartment or any personal residence; its' relevant documentation is a solid proof of home-ties.
Assets. A disclosure of your assets both personal and business. No one would leave their assets just to stay in another country. This may include bank accounts, businesses, insurances, endowments etc. e.g. if you have an important/specific medical insurance that can be used for good effect.
Residential rental agreements. You may not have a house of your own but may be living on a long term rental agreement. This is fairly practiced in the gulf countries where people have 1-2 years rental agreements for their residences.
2_ Current job. Having a permanent fix salaried job or an on going contract is also a very nice proof. You can show your current job and career buildup/advancement documentation, sometimes even a professional resume/CV with references mentioned on it works as well. This also highlights that you won't be staying illegally for work.
If you are a business-person then your business ties will replace the job related documentation.
3_ Letter from current/past employers for rehiring. This may be a long shot for you but if you have good terms with your employer you can use a letter from your company stating that they are interested in rehiring you once you come back. Of course this doesn't put a legal obligation on them but it will be helpful for your visa processing.
4_ Renewal of certain documentations. For example if you have any professional license which requires renewals; that license is a potential intent to come back to renew it. A common example of such a license can be a teaching license.
5_ Social ties. Documentation supporting your social ties and role in your community. These may be immediate family members living with you like parents, kids, step-kids, wife, custodial children etc. e.g. Documentation supporting your kids schooling can have a very strong impact.
Furthermore a link to some organization can also be used. You may be a part of some charity, a religious institute memberships
Now coming to the point that since you are a retired UK national; trust the comments, you will literally have no issues in getting visas. You are the kind of person countries want to have as visitors and tourists. :-P
(I may have missed something or if something comes to mind later on I will edit this post)
For others reading this just keep this general point in mind that proving home ties can be a strenuous process and it really depends on how you approach the visa officer and the application. USCIS has more-or-less the most thorough process for verifying home ties; they operate based on the assumption that you are coming to the US because want to illegally overstay and you have to convince them otherwise. Having a look at the requirements on their website will be very helpful for almost any country.
