I "overdose" and end up either super high or super depressed. I don't think that comes from mixing techniques, just from having a hard time with energy.

The first time I did my own hand written ceremony, I raised the energy more than I could handle and then I could not ground it properly. It took me a week to recover from the side effects(jittery, insomnia, lack of hunger, the jitteryness taking the longest) and ground the energies that chose to hang around.
Another reason why I was asking is some people I used to study with were always talking about how mixing enrgies and traditions could have serious effects. I find that if I research it enough and try in small doses at first I don't have any harm come to me.
With the mispronouncing words, that was something I was wondering about because I have heard that if you mispronounce a word it will have an entirely different effect. I have also heard that it is the intent behind the words that matters.
I have also had spells work out in ways that I did not quite expect, but still accomplished what I asked for.
I was told that depending on what your spell has to get through, It could manifest in different ways or not at all.