what i do is i start my spell with either a energy circle, stone circle, earth circle, and/or salt circle depending on the type of spell i am using. thin once i have the circle casted on the earth i visualise the ambient energy around me charging or building up in to a psi ball. while i am charging the psi ball i pout my intent into it than release the spell.
other time i draw earth a five pointed star, six pointed star, or 7 pointed star in chalk or charcoal sometime i even engrave these symbols in the earth. than do as i stated up top except weaving the energies of each point in the psi ball. but i manly use the star form if i am going to invoke a deity to add me is casting a spell.