Not everyone is a baker or wants to spend a ton of money for a professional cake. So what's a mom to do if she wants to save some money by making a cake herself, but doesn't quite cake design skills? First off, buy a package of cake mix and a tub of frosting from the grocery store. When on sale, you can often buy these for only $1 a piece. Next, buy cake decorating tips and the frosting decorating tubes they attach to that can be found at the grocery store (no need to mix food dye, the frosting is already colored!). These may cost a few dollars but you can reuse them for future cakes.
Buy a candle an reuse it. For my daughter's birthday, the "1" candle was previously used on the cake of my elder daughter when she was one years old. Next, find small cute toys around the house that can be used as cake decorations. Just make sure to wash them before putting them on the cake. If you want to add more decorations, look online. I found that little cardboard Happy Birthday cake banner on Amazon for a couple of dollars.
As for decorating with the frosting, if you'd not handy like me, then just draw a border, place frosting dots along it, and write the child's name. At the end of the day, what counts the most are having the family together to celebrate your child's milestone and the love you put into making that day special.