If you buy one thing for product photography, buy light. A modest camera under good light beats an expensive camera under bad light, and the difference is obvious to people who know nothing about photography.
The one rule that matters
A bigger light source relative to your product gives softer shadows. That is most of the craft, expressed in a sentence.
A bare bulb is a small source. It gives hard edged black shadows and a hot white spot on the label. The same bulb fired through a large diffusion panel becomes a big source, and the shadow turns into a soft gradient that describes the shape of the product instead of fighting it.
This is why a cheap light in a big softbox outperforms an expensive light used bare. When comparing kits, look at the size of the modifier before you look at the wattage.
Continuous or flash
Continuous LED is what most brands should buy. You see exactly what you are getting, which shortens the learning curve enormously. It works for video as well as stills, and it is cheaper. The limitation is raw power, which matters when you need a very small aperture for deep focus on a large product.
Flash or strobe gives far more power in a burst, freezes any movement, and overwhelms ambient light so the room does not contaminate your colour. It costs more and you cannot see the result until you take the frame.
For packs, bottles, jars, cosmetics and most e-commerce work, continuous LED is the right answer. We use both, and for a brand setting up in-house we would recommend LED almost every time.
A kit that covers most products
Two lights. One as the main light at roughly 45 degrees to the product, one to fill the shadow on the opposite side at lower power. Two is genuinely enough for the large majority of listing images.
Two large softboxes. Bigger than you think. A 60x60cm box is a good starting size for products up to bottle scale. If you shoot larger items, go bigger.
A white reflector. A sheet of foam board costs almost nothing and does the job of a third light. Bounce it into the shadow side and you often will not need the second light at all.
Diffusion fabric. For reflective and glass products you will want to shoot through a large diffusion panel rather than pointing a softbox at it. This is the single technique that separates a competent glass shot from a bad one.
A grey card. Trivial cost, and it sets accurate white balance in one frame. Colour accuracy is the difference between a product arriving as the customer expected and a return.
What to check before you buy LEDs
CRI, the colour rendering index. Look for 95 or above. Cheap LEDs with a low CRI render some colours badly, and you find out when a red pack photographs orange and no amount of editing pulls it back convincingly.
Flicker. Cheap LEDs pulse with mains frequency, which is invisible to your eye and shows as banding across the frame at faster shutter speeds. Test at 1/200 before committing.
Colour temperature consistency. Two lights from the same box should match. Two lights bought a year apart often do not, and mixed colour temperature across a range is a slow, annoying problem to fix in editing.
Stability of the stands. The most expensive thing in your studio is the product on the table. A light stand falling into a client's product is a real cost.
The light tent question
A light tent or shooting box is a fabric cube you light from outside. It gives even, shadowless light on small products with almost no skill required, which is genuinely useful for a large catalogue of simple items.
The tradeoff is that shadowless light looks flat, and flat is not the same as good. Products end up looking pasted onto the background because there is no shadow anchoring them to a surface. For a hardware catalogue that is a fair trade. For anything premium it is not. We cover this in more detail in the light box guide.
What you can skip
Coloured gels, unless you are doing creative work. Ring lights, which are made for faces and give a distinctive circular reflection that looks wrong on packaging. A third and fourth light, until two have stopped being enough. Expensive branded stands.
Natural light as a starting point
If the budget is zero, a large window with the direct sun off it is a very good soft light and costs nothing. It has real limitations, mainly that it changes hour to hour so a catalogue shot across a day will not match. Working with natural light covers how to get the most out of it and when to stop.
If you would rather not build a lighting setup at all, our studio is set up for exactly this and works on a courier-in basis.