Strawberries: (or any berry) Wash them whole. Lay them on a kitchen towel and let them dry. Then, spread them on a cookie sheet, greens and all and cover completely with foil or plastic wrap. Put them in the freezer until solid. When they are completely hard, put them in a freezer bag. They won't stick together this way or get mooshy from the water. The green part of the berry has nutrients and tastes just fine in smoothies. I got a killer deal on some organic berries from my SIL, $1 per pound (yep) so I took a gaggle of them. Now I wish I took more. They were amazing.
Plums: Easy as pie. Just wash them, dry them slightly then cut them in slices away from the pit. Put them on a cookie sheet and freeze just like the strawberries. Put them in the freezer bag when hard and use in smoothies. They are wonderful. I have a tree full of them and never knew how to use them all up before. I have a crazy hybrid melon in my garden right now, a cross between a cucumber and honeydew (affectionately called a dewcumber) and it juices up perfectly with these plums. Somehow freezing them makes them taste even sweeter.
Peaches: peel and slice them, either with a peeler or blanch them first. put the slices in water with some lemon juice for a few minutes. Drain then put them packed together tightly in a freezer bag being careful to keep the air out. They will stick together so use smaller bags.
Grapes: Wash, dry then put in a bag to freeze. If you haven't tried this before, you will be amazed. They taste like candy. The kids will love the. Watch for great deals this time of year on organic varieties. I found many for under $2 per pound. Non organic varieties can be found for under $1 this time of year so stock up.
If you are looking for local organic here in AZ, try the ranch market on Power and Warner or try the Backyard Farmer who delivers fresh picked fruits and veggies to your door weekly. He also has deals on buckets for grains as well. Email him at email@example.com. He will email you the weekly order form. There are plenty of local farmers markets so check online for locations. Try swapping with neighbors with produce you grow also. I HATE to see great organic produce falling off the trees being wasted. Pass it on