The freeze is a draw that stops right against another stone: bracket the weight, dose the sweeping, know the drag effect and avoid the raise.
The honest answer: a freeze is a draw that stops right against another stone [1], more precisely directly in front of and beside it [2]. You want to touch it but not move it. That makes it the finest weight shot in curling: if your stone stops a bit short, you simply have a normal draw. If it is too heavy, you push the target stone away and the freeze becomes a raise (a draw that bumps another stone forward [1]).
Tactically the freeze is popular because the opponent can hardly hit the stone without moving their own. But it is not untouchable: there is the drag effect. If the opponent strikes the front one of the two frozen stones from the side, they can take the back one along [3]. Important for planning: even a perfect freeze does not protect you from every hit.
How hard is it? It requires a reliable draw and a clean release. Realistically you need many repetitions before you can judge weight to within a few centimetres. There is no time promise.
First throw one deliberately a little too heavy: you see how the target stone moves (a raise [1]). Then throw one deliberately a little too light, so your stone stops just short of the target. After three to four throws you know the range in between.
Milestone: you touch the target stone without clearly moving it in three out of five tries.
The aim point is the front edge of the target stone, not its centre. Your stone should "knock", not "bump". Decide before the throw whether your stone should end directly in front of or beside the target [2].
Milestone: the stone stops no more than a hand's width in front of the target stone in four out of ten tries.
On a freeze the sweepers are part of the fine tuning. In an ice-chamber study the sweeping style changed the stone's travel distance at the same speed [5]. That means small doses give centimetres. Agree beforehand when "Hurry" is called [1] and when the sweepers stop. Do not push it onto the target, bring it to the target.
Milestone: five freezes with sweeping help, three of them without moving the target stone.
Before you play a freeze, ask: how easily can the opponent undo this? The drag effect lets them take the back stone along with a sideways hit on the front one [3]. The US federation's instructor manual also warns: never play a "bump" on a come-around freeze [4].
Milestone: before the throw you can say which hit the opponent would have.
Play series in threes: the skip holds the broom, you throw, one sweeps, one measures. Count how often you land in the "contact zone". That teaches you to handle nerves.
Before the freeze, ask yourself: can the opponent hit the front stone from the side and undo my freeze? The drag effect turns a seemingly safe pair into a throwing path: depending on which side of the front stone's nose the opponent strikes, the back stone goes left or right with it [3]. Plan the freeze so that this line leads nowhere.
A freeze is a draw variant that stops right against another stone [1], in front of and beside it [2]. It makes it hard for the opponent to remove the stone without moving their own. If it is too heavy it becomes a raise [1].
A draw stops in or in front of the house [1]. A freeze is a draw that ends directly against a stone [1]. A takeout removes a stone from play [1]. Freeze and draw need feel, takeouts need speed and contact.
The weight comes from the push-off, not the arm. For the freeze you bracket the range: once deliberately too heavy, once too light, then the middle. For the last centimetres the sweepers help, because sweeping changes the distance travelled [5].
Hit and Roll in Curling: Hit and Roll to the Right Spot