Identify irreversible steps

Walk the order you mapped and mark every step you cannot take back once it happens. Those one-way doors constrain the rest: cheap reversible moves can go early and be tested freely, while a step that spends something permanently should wait until it has the information it needs.

Walk the order you mapped and mark every step you cannot take back once it happens. Those one-way doors constrain the rest: cheap reversible moves can go early and be tested freely, while a step that spends something permanently should wait until it has the information it needs.

Example

In the statistics plan, reading the worked solution is the one-way door. Once you see it, that problem can never test you again. So you attempt all 12 problems cold first, and only then open the answer key.