Commonly written as TF*, it means “Trade For Something”. Typically it’s TFPrints or TFCD (disc of images). All photographers have their own rules, requirements, and systems for sending images, so it’s something you need to work out with each individual prior to scheduling a shoot. The purpose of a trade shoot is for all parties involved who are working on a trade basis to benefit from the shoot. Keep that in mind when scheduling trade work.
A test shoot it typically a shoot where a photographer wants to try a new technique or piece of equipment. In some cases, it nets 0 images, and in others it produces great results, but because it’s a test of something new, it’s not guaranteed. Some photographers do paid tests, others do unpaid tests. Again, it’s something that needs to be discussed on an individual basis prior to scheduling.