Hoi An is loveliest when you do not try to see it all. Here is a two-day suggestion — to feel, not just to tick off.
Day 1 — Heritage
Walk the Old Town early while it is still quiet: the Japanese Bridge, century-old houses, a bowl of cao lau in a narrow lane. In the afternoon, learn to make a silk lantern. At night, float a paper lantern on the Hoai River.
Day 2 — Sea
A late morning on An Bang beach, coffee at the waterline. Seafood for lunch. Cycle through the Tra Que herb fields in the afternoon and pick vegetables with the villagers.
The Annam Beachfront is the ideal base — close enough to the old town, far enough to keep the calm.