Easy ways to get people back after they leave!

Gwen: Ship 10 fish and 20 crops ( any kind)
Eve: wait till summer and ship oranges and bluberries
Ronald and Dan: 9 fruits in one day.Carl and Katie: ship many eggs, mayo , and milk.
Ray: ship ALOT of fish every day.
Lyla: ship 9 flowers in one day

how to get shops to open:

Sibara: ship good clay
Lyla: ship nothing but flowers every day!
Pardise orchard: plant a grape tree and ship one grape.(bears fruit sometime in fall)
Perch inn and moonlite cafe: go to the first spring horse race (17th)and meet doug and duke both shops will open on summer day 1.
Sanitorium: ship 30 herbs and have alex to at least 1 heart.
Blacksmith: ship a bunch of ores every day untill u get a note saying that it is open