Rent your stuff
Have you got stuff you could rent out. If you are not using it, then why not rent it out.
Whatever you have, from cars, boats, bikes, holiday homes, camper vans, tents, tools, ladders, parking spaces, beach huts, aircraft, rent it out.
Rent your Place
Have you got some property you would like to hire out? Rent out your holiday home, beach hut, shed, garage, off road parking, workshop space.
If you are not using it, then why not rent it out.
Rent your Tools
Have you got tools you rarely use. Then why not rent them out. Farming, building, engineering, medical, marine, automotive the list goes on.
If you are not using them, then why not rent them out. Or share the cost of investment.