An interesting alternative to Scary Sharp
Many woodworkers have been using what is referred to colloquially as the "Scary Sharp" method to sharpen their hand tools for a while now. This method involves utilizing various grits of sandpaper on a solid, flat surface to sharpen as opposed to using traditional stones.
There are debates raging amongst woodworkers as to how economical this is over time and as well as several more nuanced opinions on the merits and downsides of sharpening with this toolkit.
Rex Krueger offers a different option which involves exceedingly inexpensive diamond stones.