SNEAKY PALM OIL
It turns out that palm oil sneaks into over 50% of packaged goods. You'll find it in cookies, peanut butter, breakfast cereal, cleaning products, laundry detergent, lipstick, and body lotion, among a variety of other products.

What's especially aggravating is that you won't see the words "palm oil" listed on many of the ingredient labels.
Sneaky companies know that palm oil is facing a massive backlash, so rather than switch to a more environmentally/human/animal friendly substitute, they're clinging on to their profit margins by hiding palm oil behind a ton of different names.
For example, they'll often list "vegetable oil" as an ingredient, even though that vegetable oil is a blend that, more often than not, contains palm oil.
www.RAN.org has helpfully put together a partial list of names for palm oil-derived ingredients:
PKO - Palm Kernel Oil
PKO fractionations: Palm Kernel Stearin (PKs); Palm Kernel Olein (PKOo)
PHPKO - Partially hydrogenated Palm Oil
FP(K)O - Fractionated Palm Oil
OPKO - Organic Palm Kernel Oil
Palmitate - Vitamin A or Asorbyl Palmitate (very common in breakfast cereals)
Palmate
Sodium Laureth Sulphate (Can also be from coconut)
Sodium Lauryl Sulphates (can also be from ricinus oil)
Sodium dodecyl Sulphate (SDS or NaDS)
Elaeis Guineensis
Glyceryl Stearate
Stearic Acid
Chemicals which contain palm oil
Steareth -2
Steareth -20
Sodium Lauryl Sulphate
Sodium lauryl sulfoacetate (coconut and/or palm)
Hydrated palm glycerides
Sodium isostearoyl lactylaye (derived from vegetable stearic acid)
Cetyl palmitate and octyl palmitate
So what's the easiest way to avoid supporting rainforest destruction?
Avoid packaged goods.
It's a pain in the ass but sometimes convenience just isn't worth it.