Allocate resources to specific activities. Pay Grandma's airfare to visit while Mom and Dad go on vacation. Grandparents save all year and pay for themselves and their grandchildren to attend our Grandparent-Grandchild Summer Camp. To keep an attachment going over distance is to be creative in becoming as much a part of your grandchild's everyday life as possible. Then, when you get together in person, there will be no gaps in time where you did not know exactly what you both were doing.
Young children grow and change quickly.
Happily, this changes quickly after a couple of days together. Keeping the connection going is critically important. Technology is a blessing to long-distance grandparents. Lots of kids are computer literate. Grandparents must become computer literate too.