I'm a newbie, 33 y/o man who intends to cast a love spell tomorrow night, during the supermoon, on the mother of my son. I have every confidence that it'll work. We were once completely and fully in love and she has shown on lots of occasion that she still loves me to a lesser extent than she once did. I still love her completely but have kept this to myself for fear of making myself look desperate. I've never cast a spell before but intend on being thorough in my prep/casting. Does anyone have any insight or advice. Feel free to ask questions that you feel are relevant to the situation.
Not about the spell but maybe you can try the basics first to make sure the spell works. In very rare cases I agree with a love spell but this one just sounds ok.
First start with the basics of magick and how to balance your inner energy to have it attuned with the flow of energy around you so that your chances of success would go up. Relax your mind and meditate. Clear it from all the negative thoughts and cleanse your chakras. Other than that you can store energy through grounding (basically using the earth's energy to charge yourself) and keep your faith up. Belief is the tool in every spell.
I would recommend using other tools such as herbs or incense with the spell or ask your deity to guide you or pray for success.
Also, once you're done with the spell, imagine the scene where the spell has worked and you've gotten the results. Picture it clearly in your mind and believe that it will happen. After that, just wait till the universe responds back to you.
Assuming you've already studied and practiced a bit. I would say you should have started prepping and planning about a week ago gathering material, as this helps lay a basis in your mind. It's the difference between throwing water in a balloon and throwing a ball of water. Having done this, ground and cleanse yourself, then cleanse a space, after which you may choose to ground and center again within the space. Then I would start your well thought out spell under the eye of the full moon.
If you still love her and want to get your love back than love spells is best for you. In your post you said that she still loves you. In this situation you need to convince her and tell her about your feeling. May be it will work for you.