This is something that many people will have trouble with, its natural, especially if you've never cast a spell before.
There is no set-in-stone way to cast spells, each person will have to learn their own way. because its something your body is not accustomed to, like riding a bike, or shooting a bow. you first must learn, you may fall, or miss your target, but you must keep trying.
Here is the bad news, Magic is not what people say it is, its not bolts of lightning and killing people with only shadows. This is possible, but a spell such as this would leave even trained minds weak.
you must start with basics and you must understand magic.
Firstly. AND MOST IMPORTANTLY.
you should familiarize yourself with the laws of magic.
This is all great and useful information. Use it.
The law of knowledge. the first law of magic.
Knowledge is power.
understand these laws, and you can begin to understand magic.
For all of you out there who think magic is commanding the elements.
The elemental gods DO NOT TAKE COMMANDS. a spell is a way of asking the elements to act for you. and they choose if they will or not.
its not just as simple as asking them, they must hear you and not with your voice, with your spirit, with your will.
the words, candles, symbols, and runes used in spells are tools. tools that help us tell our spirit what to ask for.
before you cast any spell.
Select your spell carefully.
either write it yourself, or select a spell that most fits your intentions.
know exactly what you want to do with this spell. and fully intend to have it done.
Second Meditate, see the spell through from beginning to end, over and over again, until you have a perfect visual of what you hope to accomplish.
third. Prepare for your spell,
Make sure you have everything you need, and wont be disturbed.
Fourth. Cast your circle, whether it be calling the corners or invoking a god, cast your circle.
Fifth. Cast your spell, just as you had visualized.
Finally, Thank all spirits, gods or anything that you have called upon for coming.