I have bought four tripods. The first three were mistakes and the fourth cost more than the first three combined, which is the entire lesson in one sentence and is not much use on its own.
Here is what I actually did not understand.
The head and the legs are separate decisions
This is the thing nobody told me and it explains most of my bad purchases.
A tripod sold as a unit at a low price is generally a set of adequate legs with a poor head, because the head is where the cost is and it is the part buyers do not evaluate in a shop.
The head determines whether your movements look intentional. The legs determine whether the camera is stable and whether you can put it where you want.
Buying them separately, with most of the budget on the head, produces a dramatically better result at the same total cost. This is standard practice and it is not obvious from how products are marketed.
Fluid heads and what fluid means
A fluid head contains a damping mechanism that resists movement smoothly, so a pan starts and stops gradually rather than jerking.
The difference between a real fluid head and a cheap head described as fluid is immediately visible in footage. A cheap head has stiction — it resists, then gives way suddenly — and every pan begins with a small jolt.
You can feel this in a shop by making a slow pan and watching for the moment it breaks free. A good head has no such moment.
The other thing that matters is adjustable drag. Different shots want different resistance, and a head with a fixed amount forces you to adapt to it.
Counterbalance is the feature I did not know existed
A head with counterbalance holds the camera's position when you tilt and let go. Without it, a tilted camera falls forward or back under its own weight.
Which means every tilt is a fight against gravity, and holding a tilted position requires locking off, which means you cannot adjust during a shot.
Counterbalance is matched to camera weight, which is why heads specify a payload range. A head balanced for a heavy camera will not hold a light one and the reverse.
This was the specific reason my third tripod was unusable with a lighter camera I bought later, and I had no idea it worked that way.
Legs, and the things that actually differ
Less critical than the head and not irrelevant.
Height matters more than the specification suggests. Maximum height with the centre column down is the useful number, because extending a centre column reduces stability considerably.
Minimum height matters for low shots, and a lot of tripods cannot go low at all because the legs will not spread far enough.
Leg locks come in two broad types, twist and flip. Twist locks are more compact and slower. Flip locks are faster and catch on things. This is genuinely a preference and worth trying both.
Material affects weight and price. Carbon fibre is lighter and considerably more expensive and dampens vibration slightly better. Aluminium is heavier and cheaper and perfectly good if you are not carrying it far.
The bowl, which nobody explains
Video tripods generally have a hemispherical bowl where the head mounts, which allows levelling the head independently of the legs.
This is enormously convenient. Levelling a photo tripod on uneven ground means adjusting three leg lengths. Levelling a bowl means loosening one clamp and tilting.
Bowls come in standard sizes and the head must match the legs. Buying a head and legs with different bowl sizes is a common and irritating mistake, solvable with an adapter but better avoided.
What I would buy now, at three budgets
At the lowest end, a used professional head with basic legs beats anything new at the same price. These things last for decades and the used market is full of them.
In the middle, a proper fluid head with fixed counterbalance matched to your camera, on aluminium legs with a bowl. This is where most people should be and it is a purchase that lasts.
Higher up, adjustable counterbalance and carbon legs, which matter if your camera weight varies or if you carry it a long way.
What I would not buy at any price is a combined unit from a general electronics manufacturer, which is what I did three times.
The wider point about kit
Tripods are a good example of a category where the expensive version is genuinely better and the improvement is in something you cannot see in a specification.
Smoothness of movement does not appear on a list of features. It is felt in the hand and seen in the footage, and it is the entire reason the price differs.
Which is why the advice to buy cheap and upgrade later works poorly here. You do not learn what you are missing from the cheap one — you learn that your pans look bad and assume you are doing it wrong.