You have to decide on which type of spell you're looking for
If it's spell to call for something, you must write it during a waxing moon (New to full moon)
If it's a spell to banish something, you must write it during a waning moon (Full to New moon)
You can include your deity & also elements invoking into the spell.
Many spells end with "Mote it be!", but it's up to you.
Focus your will and intent. Spells only work if you believe that they do.
Whenever possible, follow Nature's natural Energy Currents. There is a natural
time for starting things (a planting time), for maturing things (a growing
time), for reaping things ( a harvest time) and, of course, a time for rest and
Flowing with these currents will make your magickal work much easier.
Remember that Magick is the manipulation of energy, a thought is a form of
energy and a visualization is an even stronger form of energy. Your
visualization can be a method used to intensify further and direct your will.
Your visualization can be the method by which you control the magickal energy
you have produced. You must know what you want. You must see it. You must feel
the high-energy flow. You must direct it.