Sharing tools is the alternative to investing in equipment. It allows to use expensive machines or tools without having to buy them.
There are three main ways of sharing tools: sharing websites, tool libraries and shared workshop spaces.
Sharing websites are not specifically made for tools and allow you to borrow a tool you need from people in your neighborhood. Famous examples are Peerby or Streetbank, although different websites are more active in different places.
Tool libraries are popular in US cities, and basically just extend the book library model to tools. Look for similar initatives in your area, and you may be surprised.
Finally, there are shared workshop, like FabLabs, TechShops, Makerspaces and countless local initiatives that go under different names. In these workshops you pay a membership fee in exchange for the possibility to use tools and digital fabrication machines, trainings, and the possibility to interact with other designers and makers. Find the one nearest to you before you invest in that expensive machine.
Find the digital fabrication workshop closer to you on FabHub
Shared machine workshops: FabLabs, TechShops, Makerspaces (Dutch: RDM makerspace, iFabrica, US TechShop)
Tool sharing in your city? Globally Peerby, Streetbank and locally Zero Relativo (Italy), Leila (Berlin), Ecomodo (UK),
Examples on Superuse.org
Examples on Harvestmap.org