let me try.
in my reality everything is cause-effect. what you do is conditioned by your previous experiences, beliefs - reality tunnel. the thinker thinks, the prover proves. if you expect to see shit, shit is what you will get. this is why control over your thoughts and emotions is important. try puting yourself in some situation, first with a smile on your face and then soaked with fear. are the outcomes the same? seeing that everything is relative and can be influenced is big. our minds are mostly programmed to go through life doing things that are most obvious for us to do, what we believe is the right thing to do. but where do your beliefs come from? why do you believe all those things anyway? why do you hold to hold to believes that limit you? you are but a giant living in a pygmey hut, why do you spend the days bent under the short ceiling, break the walls and go for a walk. (love quoting robert anton wilson, google him) one could suggest that believes therefore limit us, but why not seeing belief as a tool to program reality? this idea is the core of chaos magick paradigm. but since belief functiones on subconscious level of our mind, it is not easy to reprogram it. one has basicaly bypass some of the minds filters to acces subconsciousness.
this is where the altered states come in. most common form is gnosis. it can be achieved by meditation or sleep/food/sensory deprivation or intense sexual arousal, dancing, drumming,... sigil is a basic example of such reprogramming. an intent is formed and aranged into a glyph which is used to meditate upon when reaching gnosis. and then forgetting it. it will work without me consciously knowing it. sigil is basically a magick ritual stripped to its core. traditional magick only uses many often dramatical subconsceous triggers to imprint into a willing mind in the state of gnosis. these triggers are symbols, intent translated in the language of the (global) subconsceousness, often using powerfull corelations that human mind has developed. (at this point i recomend reading on memetics, it can blow the mind) but what does all this have to do with controlling the emotions? isn't this even more messing with the mind instead of just shutting the chatter and go with the flow? only if you choose to view it as such. or you can see it as a technology to modify yourself and the world, to explore the limits, manifestation of glory so to speak. as above so below.
this is what i imagine as a brief map of my beliefs about magick.
more related brain food:
-robert anton wilson - simply genius, read the prometheus rising - a owners manual to the human brain
-peter j. carroll - liber null and psychonaut - provides a objective view on magick rituals and magickal path
-chaos magick - google it
-psychology: timothy leary, carl jung
-memetics: art of memetics for a more occult view on memetics
-deoxy.org is a tasty sauce
hope this helps