I found the handiest little gizmo at the drugstore one day while waiting on a prescription. It's a French fry cutter. Not only do I use this to cut homemade French fries, but also when I'm freezing diced bell pepper, onion, etc.
I wash whole, fresh veggies in tepid soapy water; rinse, and dry. I de-seed my bell peppers and cut into pieces large enough to fit against the cutting blades of the French fry cutter. Press down the handle and voila! - freshly diced bell pepper!
I allow everything to drain in a colander for a few hours, and then spread out onto cookie sheets and place in the freezer. When the veggies are completely frozen 'unstick' from cookie sheets using a spatula and then place into freezer bags or freezer storage containers.
By Juanita from Enid, OK