A studio is just a room. It’s how you set it up that determines whether it’s a studio or not.
My kitchen is quite useful as a studio because the ceiling has been painted white. This instantly gives me a huge light source from above, which is perfect for lighting products. I usually bounce a couple of flashguns off it, and have them on light stands high up above shooting level. This pretty much eliminates any danger of lens flare caused from stray light from the flash heads.
In this case I’ve used two flashes, just so that I can have them on half power and don’t need to worry about recycle times or changing the batteries, but a single one will do the job too.
My kitchen walls aren’t painted white, but this doesn’t matter as I’ve built a hinged tabletop out of chipboard that lets me drape over a roll of white paper for a background. I’ve also bought a few A4 white foam board pieces which I’ve taped together to provide me with some cheap, portable but very effective reflectors. I’ve also taken a sheet of glass out of an old picture frame and used that as a base in order to get a reflection of the products I’m photographing.
Thats pretty much all you need, and the results you get are surprisingly good. There’s no dependency on ambient light at all, it’s a completely consistent setup regardless of time of day, and it can all be assembled ready to go in less than 15 minutes.
What’s also important is that because it’s so simple you’ve got consistency across different days of shooting. Images that you shoot using this ‘studio’ in January will be under exactly the same lighting conditions as those that you do in June, and this is important if you are doing work for catalogues or websites where products are continuously being added or updated over time. They should all look the same.
All in, including the flashguns, light stands, tables, paper rolls and cards I reckon you could set this up for under £200. It’ll pay itself back very quickly.