Today let us suppose you are the Supreme Being of your Omniverse! You may be the single creator and ruler of your own world and posses unquestionable authority and power over it or share supremacy with your dark twin. You can go with any abilies you'd want from casual Reality Warping to particularly infinite Omnipotence, Metapotence and Complete Arsenal.
What powers you have as a Monotheistic Deity? Describe in detail your tools, so we could understand it finely. You can choose anything you want, even True Omnipotence itself if you want!
How would you create your world, how vast is it (single universe, multiverse, megaverse, ... Infinite Omniverse), how would you do it? Describe your vision of how the totality of creation started and how you set all of this in motion!
What rules, laws and design you'd create your world with? Maybe, there's something you won't approve by any means and you forbid it for the whole eternity? Describe the ultimate pataphysics behind everything!
What lifeforms your world is filled with? How did they originate: they were supernaturally created by your providence or evolved naturally? Who are those beings: angels, demons, genies, dragons, humans, cosmic beings, transcendent beings, abstract entities or anything else? Do you reveal yourself yo them? If yes, how do they relate to you? How do you relate to your creation?
And finally...
How would you spend your eternal Monotheistic Godhood? Maybe, you'll constantly create and conceptualise new things to add them into your world via Primordial Force Manipulation and regeneratively end existence with Apocalyptic Force Manipulation to re-begin it again completely new and hollow? Or you'd preserve your world for the whole eternity and become its keystone? Probably, you'd like to share your possibilities and gifts with your creations and become their heavenly parent and generous source of any goodness? Describe yourself as Supreme Being and represent your best vision of yourself!
Who would be your allies for the whole Eternity? Who will be lucky enough to spend your Godhood alone with you and represent the image of your eternity? Would that be Primordial Gods, certain transcendent beings or anyone else? Would they attain the gift of Absolute Immortality, Absolute Reincarnation or Eternal Existence? Maybe, some of them would transcend their limitations forever and eternally to become closer to you in godly relationships? Or you don't want undying campaigns and would constantly switch them?
Note: don't create utopian world, it's boring and not generally creative. Unless it's part of something even greater and plays its role in your greatest scheme, I don't recommend you to choose this boring option.
Additionally, I would like to invite our special guest, legendary @DYBAD to participate our discussion. We'll share different ideas for Supreme Being writing and possibilities of creation of everything and what Monotheistic Godhood would be. We'd love to hear your opinions! Thank all of You for participating! Feel free to use any of these ideas I found here in your worldbuilding and character writings!