I know I'm not the first one with a sharpie DIY, and that there must be thousands of these floating around on the internet. I hope no one will object to one more. In my opinion, the best DIY's are the easy ones, that don't take up a lot of your time and the ones that don't need lots of supplies to make. All you need for this one are a plate, a sharpie and an oven.
Start by making ovals
Don't forget to bake your plate for half an hour at 150ºC / 300ºF
I do my dishes the old fashioned way, but once baked, it should
You can find more DIY projects over here.