I mostly run Windows to work with engineering software, but I often have to access my Mac Mini for testing code or cross-platform programming. I don't like to change between computers, so I sometimes use a remote desktop solution.
In the Mac OS X control panel, turn on Screen Sharing, File Sharing, and Remote Login.
Then, download and install VNC Viewer. (Yes, I know: this is not free and open source software, but it works so well on Windows that I like to use it.) You do not have to run and download VNC server on the Mac machine since there is a remote desktop server already built in to the OS.
Ensure that the Mac machine has a static IP address on the network. Then in VNC Connect, add a new machine.
You can connect easily to the Mac machine by clicking on the icon provided in the main window of the software.