If you are heading for a summer-vacation rental, here is advice from New Jersey designer Rosemary Niklaus, who has helped dozens of families prepare for shore retreats.
There are two things to remember, she says. Keep your personal additions to the rental minimal, adding only what you can take down in an hour's time. And don't buy anything for a summer house that you can't use at home the rest of the year. This is one time, she says, to remember that beauty is only surface deep. While you will want to bring a touch of your own personal taste to your summer rental, she advises, ''Don't make any major investments, and buy only what you are willing to throw away at the end of the season, or take home in the trunk of your car.''
Here are six of her best ideas:
* Brighten the floor with a rug, perhaps a flat-weave kilim, which looks terrific but folds up easily to fit into a car.
* Make temporary slipcovers from bed sheets in cheery patterns by simply tucking them tightly over and under cushions in chairs and sofas.
* Curtain the windows to match, using pushpins to swag the sheets across the tops of window frames and a length of grosgrain ribbon to tie them back.
* Buy a couple of inexpensive plain, white lamps from the dime store.
* Buy or bring at least eight attractive place mats and napkins to dress up the table.
* Don't forget your own bed pillows. You'll sleep better with them.