Then, once you've done that, double that amount of the reserve, just for the exercise of it. Because most of us only develop 'more than enough' instead of a real reserve. Make a radical change of some sort, just to rattle your cage or life. This can begin the process of change in other areas. Most of us are stuck in inertia, and by making a radical change in one area, we get some momentum.
Momentum is important to building a reserve.
Become an investor rather than a spender. This can be as simple as turning a hobby into a business or spending money to start a business instead of always eating out. Find something 'better' to do with your time or money. Grab stuff even if it makes you feel guilty. If you like a person, 'take' some of their time and use it for your personal benefit.