The one thing to note is the value you are trying to find or edit could be stored as a floating point. So if game hacking is something that's of interest, it pays to take a look into the floating point structure/how they work.

Anyway it's nice to see a tutorial like this. Though it's only scratching the surface, the next thing you might like to do is create a standalone hack for it. So for that you'll usually want to find a static address, this can either come from finding what routines are referencing/making use of that value, and then reversing those routines and determining what should be edited, or seeing if there's some data references to it (either pointer or if the value is actually located within) from one of the static sections. Though then there can sometimes be the issue of section or segment randomization, which is a whole other thing to work around :P.