I'm far from an expert, but I think my food photos have improved immaculately.
While a lot of food photography is actually using your camera correctly, you can really help your photos by finding some great props. It's kind of become a slight obsession of mine now to look for things I could use wherever we go.
Dollar Stores
At the dollar store, you can buy single plates, cups and bowls for $1. But... do you think about what else you can get there? Grab a roll of wrapping paper for a nice back drop. I have a couple of "wedding" design wrapping paper rolls that are just striped or small really light circles. Also, check in the dish aisle for shelf liners. You can get adhesive shelf liners in different designs that will allow you to make your "table" granite or various wood patterns.
If you need something seasonal for a few added props in the background, you can grab them at the dollar store without breaking the bank.
Yard Sales, Flea Markets or Consignment Shops
When you're at Yard Sales, Flea Markets or Consignment shops, keep an eye out for things that you can use.You'll be able to find clear glasses, random plates, bowls and napkins for super cheap at these sales. If you go to a store, you'll usually have to buy a set, but not at a yard sale! I'll also group Goodwill into this because you can find some great pieces there that are sold individually.
Look for oddball white dishes (they're best for most of your food) in different shapes or with different designs. Antique plates can bring a completely different look to your food photos. I've really added to my collection while paying about .50 for each dish.
Ebay
When you figure out what it is that you want, search for it! If you add primitive or antique to whatever it is that you're looking for, you'll be overwhelmed with great possibilities.
Finding a lot (meaning a large group of items) or a few items from the same seller is probably your best bet on ebay.
Retail Stores
In a craft store, or even Walmart, you'll find so many great options. Try not to get too crazy though. Simple is best when it comes to your food photos. Anything you get shouldn't take away from your food, so keep that in mind while you're going crazy throwing things in the cart.
I've been buying Fat Quarters (fabric pieces) instead of fabric napkins. I can pick them up for much cheaper than napkins and they're larger if I wanted to cover my whole "table" with it.
Holiday Clearance
I've been really lucky lately finding super cheap clearance on holiday items. I'm still finding Valentine's Day items and Christmas items! I paid 10 cents for a pack of 10 paper straws last week and found a few more packs this week! I love being able to sneak a little color into a picture with just a straw. The pop sticks were 10 cents, too!
Where do you find your props for food photos?