Here are some of the files we were given to construct a pizza:

First I removed the background and added a tablecloth that reminded me of an Italian restaurant.  I created a new layer for sauce and painted it on with brush 100 set to scatter and made sure to make it a little messy up against the edges like real tomato sauce.  I used the dropper to grab realistic colors from a stock photo of sauce, and added some basil and other sauce spices with brush 35 set to 10% hardness and also again with a size 4 brush on dissolve.  For the shredded cheese, I first search Brusheezy, but when I didn’t find a good option there I used a grass brush already in Ps to place the cheese instead.  Then it was time to use the Quick Selection Tool/Magnetic Lasso to cut out all the toppings and place the layers in ingredient folders.  I made sure to scale and rotate the ingredients to look realistic.  Bon appetite!

Tool: Photoshop

And just for fun … a Pizza Blaster!