How do you get a spell?

First decide what form of magic you want to do. Spell, potion, visualisation, are just a start.

Second decide what purpose you want. Prosperity, peace, healing, whatever you want to do.

Third, research the moon house and phase you will have the best chance of positive results with.

Fourth, research what tools you will need to perform your magic.

Fifth, research what herbs, incense, oils, and other things you will need.

Take the time to write out your spell, determine the gods/goddesses you'll petition, the forms and movements you will need to do, who (if anyone) you want to include for their help. etc.

Then you gather everything together, work in the correct phase and house of the moon and follow your spell to the letter.

When you are finished, enter your spell in your Book of Shadows (you may some day need to do it again or in some cases you may need to reverse it). Then most importantly of all, live in accordance. Believe it will happen and go about you life.