We try to avoid all useless calories and heavy carbs like chips, pretzels, bread, etc.
We have a pool and love to have pool parties.
We often grill asparagus and wrap paper thin slices of prosciutto around them, have a variety of cheeses (we'll then offer a high fibre, whole grain type of cracker) olives, roasted garlic, those sorts of things.
We sometimes do leaf lettuce wraps (filled with any sort of things, grilled shrimp, whatever lends itself to being wrapped!) and small bites like grilled scallops, etc.
We really enjoy seafood and it is healthy, so we try to incorporate that per availability of the season. If you choose seafood that is in season it is quite cost effective.
We also do platters of grilled vegetables (peppers, seasonal squashes, mushrooms - all varieties, and even sometimes romaine).
Once you get the hang of substituting healthier food for empty calories/low/no nutritional choices, it becomes a way of life. Not only do your friends thank you, but your body does too!
Oh, we do add dark chocolate from time to time and red wine.

Depending upon the gathering, we'll do red wine spritzers sometimes.
Anyway, all that to say, it's really nice to offer things other than the usual. You're a good friend!
