I tend to not view it as altering fate, but contributing to it. You see, fate isn't something concrete in my path, but there are definitely things that happen for reasons.
Have you considered the possibility that what we do is a part of the natural order? In every culture, there are those that work with spiritual practices and beliefs (literally, every single one in history all over the world that we know of) and there is also the belief that every single being operates on all frequencies at the same time (see subtle body theory) even if only a few (proportionately to the masses) consiously realize what we are doing. With this belief, everyone practices whether they realize it or not (though I would like to note that this is not a universal belief). Personally, I find that practicing is alright so long as you take responsibility for your actions.
You see, the definition of Magickal practice is changing reality through our will. Obviously, there are physical limitations, but the work we do sets up a path for a specific outcome to happen through altering the subtle energies that permeate every physical thing. What we change on subtle planes can reflect physically, though you have to understand the physical limitations.
To look for outcomes of your work, you have to be open minded about how that outcome could manifest, what else could effect it (and there are lots of things that could effect it), allow for time to manifest without micromanaging, realizing that Magickal practice is an aid to physical action, not a substitute, and furthering a point mentioned earlier, realizing that you are but one of many living and dead beings that make up our realities. Always, always, always account for an X factor or a variable because we cannot control everything like we can in physical science experiments because we cannot measure subtle energy. So even if something is legitimate, it will not work 100% of the time and will not work the same way every time.