Although I do not know how to make a magick ring, I can help make a ring more magickal.
I did this spell last June when I was taking my nurse's exam. Now I studied a lot, worked hard throughout my nursing training, which is going to give you the most success. The magick is simply a boost in the right direction. So make sure whatever you are trying to manifest is something you are putting mundane work into as well. As they say, you cannot win the lottery if you don't buy a ticket.
This comes from 'The Witches Spell Book: for love, happiness, and success'.
You take a ring, preferably silver and one to wear on the 'pinkie' finger. You instill it with your power and clasp it over your heart and say, 'Ring of power, shield and encircle me. Blessed be.'
I did this spell on a new moon because it is symbolic to me, embarking on a new endeavor. You could jazz up your spell according to your own needs. I used my blessed clear quartz crystal (a spell I do every year to enhance my spell work for the year). Other things you can research are days of the week, oils to anoint your ring with, coloured candles, etc according to your needs. You can also cleanse the ring with sage or bury it in salt before hand to get rid of old energies the ring has. Even getting rid of the energies by those who have tried on the ring in the store and decided not to purchase it. I wish you the best of luck with your spell casting and let us know how it goes :)