"When working in a Set Dec team, can other members of the team take photos of my work and use it in their own portfolios?"

The standard legal issues still apply - they don't own the right to do so any more than you do! The production owns all the rights. Generally, however, if you do include photos in your portfolio, a dressed set is very rarely just one person's work. It's almost always a collaboration of prop makes, sourcing, Art Department, Construction, Graphics etc. So although you may have dressed it, the other team members may feel as much ownership as you. We would say, always acknowledge collaborations / help / supervision. It's a small industry and anyone misleadingly claiming work as all their own will inevitably get found out. 

"Can I use branded items when styling or dressing sets?"

The answer to this will entirely depend on the production's clearance policy and some productions / studios are stricter than others. Every production should hire a Clearance Coordinator who will be able to answer this and we recommend insisting on some clearance guidance before you start hiring / sourcing items.

Sometimes productions will take the approach that if there are enough items and they are background (eg. dressing in a shop) then branded items can be used. Another production will want the same set dressed with fictional items. Another approach is to use the branded items, but get sign off from the companies. It gets even more complicated for action props as some brands might not want their product associated with a particular character or action. Other brands will give you free products to get some product placement in a film. There are specific companies that help with this. 

There are many variations of this, so it is imperative to check what the production's policies are. 

"Do companies want to be credited if I use their products on set?"

Another tricky question but one we've more or less answered above. The answer is... it depends on the production's clearance policy! Companies would probably love to be credited, but actual credits at the end of the film very rarely happen as the limited space is saved for really significant credits. If it's a unique item, like a photo of Elvis for example, then expect to pay the photographer and Elvis' estate something substantial. If it's a generic item that is not recognisable by design, then there should be no issue with using it as you need, without gaining permission. But never assume - always check with the Clearance Coordinator and keep a log of everything that you send to Clearance to help with any potentially tricky conversations after the shoot.