I started with 4 basic things: my cake, which was a simple devil's food cake from a mix; buttercream icing (recipe below), which I had mostly dyed green with Wilton's forest green gel, but I had reserved about 1/4 of it white; both blue and red Betty Crocker icing decorating tubes with the screw-on decorating tips; and a tub of rainbow sprinkles.
I made the cake as a 9x13 sheet cake, and since those mixes are a no-brainer, it turned out yummy (I like from-scratch cakes better, or at the least a cake mix that has been jazzed up in some way, but I didn't have the time). I then frosted the entire cake in green icing, as smoothly as I could manage (I really need to work on that!), and I went around the base of the cake using the star tip with the green icing, mostly just to cover my sloppy icing job, but it gave the cake a nice finished look. I wanted this to be from the perspective of the Giants' end zone, so I decided to make the cake like a zoom-in on that part of the field. I took my blue and red icing tubes, which I used to save me the time and trouble of having to make and dye more icing, and I approximated the Giants' logo as best I could free-hand. Then I took the white icing and, using the widest tip I had (damn, I forget what it is called, my next post will be more technical, I promise), to create rows of white icing along one of the 13" sides of the cake. I was trying to give the suggestion of stadium seating, so I did this as sort of a pyramid, but with one side (facing the "field") tiered up, and the other (along the cake edge) straight and high. It is easier to see what I mean in the picture. As an example, I think I laid down 5 or 6 initial icing rows, and decreased it by 1 each additional layer I applied. But be careful, because if you don't do this straight up, and it is leaning off the side of the cake, it might fall over. Then I took a narrow round tip and, with white icing again, drew lines on the field and added the numbers. Since this was only one end of the field, I only went up to 30 yards. My last touch was to sprinkle the rainbow sprinkles onto my "stands" to give the suggestion of spectators. They liked to roll off and onto the field, so I had to pat them into the icing a bit to get them to stick. At the last minute, I came across a package of sugar footballs, so I popped one into the center of the field.
Buttercream icing recipe:
7C confectioners sugar, sifted
4 sticks butter, unsalted
1 tsp vanilla
1 tsp almond extract
pinch of salt
-Beat the butter until light and fluffy on medium speed (you can't overdo it, so be patient, it will be worth it)
-Gradually add the sugar on low, and mix until incorporated
-Add the extracts and beat until smooth and creamy
This alone worked for me, but if you need it a little thinner, add milk 1 tsp at a time until you have the consistancy that you want...