Upgrade a corner worth doubling
A city costs three ore and two grain. It adds one net point and doubles the settlement’s normal production. Upgrading a weak corner gives a smaller economic return than upgrading a position that already supplies useful resources regularly.
Choose the location before collecting the payment. A city covering ore and grain can reinforce the next upgrade, while another city may be better if it fixes a recurring shortage or distributes exposure away from one tile.
Keep development cards as an option
With wool alongside ore and grain, you can buy development cards. Knights can move the robber off an important tile and build toward Largest Army; other cards offer different tactical opportunities or hidden points.
Buying a card trades certainty for flexibility. If the same resources are the last step toward a strong city, a random development draw may delay the more useful move. Compare the immediate alternatives rather than buying whenever the button is available.
Protect against concentration and shortages
A robber on the tile that feeds your main city can stop a large share of your income. Covering more than one productive number and keeping an eligible Knight can reduce some of that vulnerability, without eliminating the risk.
You still need wood and brick for new road access and settlements. If your opening has no plausible expansion or trading route, city production can leave you rich in a narrow set of resources with little room to add buildings.
Plan beyond the first upgrade
Four is the maximum number of city pieces. Upgrading also returns the replaced settlement piece to availability, which can help you expand again. Keep track of both limits when mapping a route to the target.
Count the eventual points from buildings, awards and hidden cards rather than assuming city production wins automatically. A compact economy still needs timely scoring decisions, and waiting for one more ideal upgrade can give a faster opponent time to finish.