Free self-guided itinerary. This is a travel guide, not a bookable guided tour.
Ancient, baroque, and the Vatican. Each is a full day on its own. Trying to do all three in one produces a day of walking between queues, and this guide will not pretend otherwise.
Ancient Rome. The imperial centre, the Colosseum, the Palatine. Book ahead or you will lose hours.
Baroque Rome. The squares and fountains, mostly free, no bookings needed, easiest to do well in a day.
The Vatican. Effectively a separate destination with its own queues and rules. Half a day minimum, and only worth it if you book.
Not booking the ticketed sites in advance. Underestimating distances — the map makes Rome look smaller than it walks. And planning anything precise for the middle of a summer afternoon.
The centre is walkable but larger than it looks; buses are useful and the metro mostly is not, because it deliberately avoids the archaeology.
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