I bought a blank dry erase board, 3 x 4 feet, from Amazon. To make the grid I used black/white patterned crafting tape. Why crafting tape you ask? It sticks well to the dry erase board, can be easily removed and does not leave any residue. If you get a magnetic dry erase board (they are slightly more expensive) you could use magnetic strips/tape for the grid.
I wanted my calendar to represent 12 months, but you could easily design it to your liking: just do 6 or 3 months and leave some space open for brain storming. That is the beauty of having a blank dry erase board: design it anyway you like it! I use this board mainly for my major business events. The individual client projects and appointments I schedule on a separate calendar on the computer that syncs with my mobile phone (ex. Google Calendar or Windows Calendar).
I am still finalizing the rest of the upcoming year with events and will be done when the new year starts! I challenge you to schedule your events for the upcoming year on a calendar to your liking. If you are interested in getting a dry erase board, click on the following link: Amazon Dry Erase Boards
Let me know if you have any questions or comments. I would love to hear from you.