I don't make any more than my regular paycheck. If I want to add another animal, or need to buy new equipment, I set money aside from my paycheck until I have that money to purchase what I want or need. That means more packed lunches, and less going out to eat with co-workers, less buying some things because I want them, rather than NEED them.
What's hard for some folks is the need to get something (usually an animal) right NOW, rather than delaying gratification until they can really afford it (ie, have proper housing set up).
Trust me, if you have to work hard to save money for what you want, you are going to appreciate it so much more.