Progressive practice locks start with two pins and let you add one stack at a time up to six. Each step is small enough to succeed and big enough to learn from. It is how the locksport community recommends building single pin picking — and the lock most people wish they had bought first.
Guide
Progressive Practice Locks
A progressive (or "progressively pinned") lock is a re-pinnable lock — usually a padlock or a Euro cylinder — supplied as a set of 2, 3, 4, 5 and 6 pin configurations, either as separate locks or as one lock plus pins and a follower so you re-pin it yourself. You master a 2-pin lock, add a pin, master 3, and so on. By the time you reach 6 pins you have single pin picked hundreds of times.
Single pin picking is a sequence: apply tension, find the binding pin, set it, find the next. On a 5-pin lock a beginner is juggling five unknowns. On a 2-pin lock there is only one decision to make, so you learn the feel of a set pin cleanly. Adding pins one by one keeps the difficulty just above your level — the same principle the belt ranking applies at a larger scale.
Five identical padlocks pinned with 2, 3, 4, 5 and 6 pins. No re-pinning, no tools — just pick the next one. Ideal if you do not want to disassemble locks yet.
One cylinder, a follower, tweezers and a pin assortment. You re-pin it as you progress, then add spools and serrated pins from a repinning kit. More work, far more mileage — this single cylinder can take you from white to blue belt.
A cutaway supplied with a pin assortment. You see and feel each added pin.
Fifteen minutes a day gets most people through 6 pins in two to three weeks. From there, a security-pin lock is the next step.
Progressive locks are practice locks — pick them as much as you like; that is what keeps hobby picking legal across nearly all of Europe (legality by country). Beginners: read how to pick a lock first, then start at 2 pins.