Firstly, I would just like to say that Esbat does not specifically mean a spell or ritual at the full moon as many people believe. It can coincide with the full moon by choice, but are not one and the same thing. For those in a coven, monthly meetings (outside of Sabbatts) are routinely held so it is convenient to hold them at the full moon to make use of the powerful energies at this time. Mostly, it's for light-hearted rituals and fun as the meaning of Esbat is actually 'frolicking'.
So with that cleared up, what can you do? There are a few ways to make use of the full moon for a spell. One way is to use it for a timeframe -if there is something you'd like to see happen for you over the next month, use the moon's energies (just make it realistic). It can be a great time to cast spells for change and transformation. Altered mind-states work well at this time as do spells centred around femininity.
Personally, I'm using it as a timeframe. I have a very important day coming up two days after the next full moon in June and have a lot to do to prepare myself in the meantime! There is a big element of chance to what I want to happen and so I need to really work on growing stronger, ascertaining what specifically needs to be done and - as ever with me - being organised enough to actually get it done.
I am decorating the altar purely in silver and white. So white candles, white ribbon, my ever present favourite Triple Moon chalice (to be filled with water), snow quartz crystals and dark musk incense. I will have a silk pouch too (pretty similar to this moon and stars one but my aunty made mine!) - and I have a special plan for this. I will be writing what I already know I need to do down on a bit of paper (separate piece for each task), placing them in a bowl and focusing the energies on them. As I accomplish each one throughout the month, I'm going to place the piece of paper in the pouch to signify its completion.
Full Moon Spell
To start with, connect with the full moon's energies. Say:
The rhythm of the earth
Is the rhythm of the moon
And is the rhythm of my life
Together, we are one
Using the incense, draw a widdershins (anti-clockwise) circle over the bowl of tasks 3 times.
Unfailing and timely
Is the moon on her journey
Her cycle replete
By example she guides me
In the brilliance of her light
Her gentleness and might
I am inspired by intention
And seek her attention
Place the chalice of water in front of you:
The element of water, your natural companion
My dreams and my life combine as one too
Hope you find this useful!