I do not know about you, but whenever i buy watermelon my family can never finish the entire watermelon within couple of days and I somehow do not like to buy already cut watermelon. Hence i tried freezing the watermelon pieces once and it all stuck together and it was a big task to separate the pieces. Later when i checked online, i found a video on how to freeze banana and i tried it out for watermelon and it worked perfectly. The pieces did not get stuck to each other and when i wanted to make a smoothy, i could easily use how many ever pieces i wanted, without any struggle. I know few might feel it silly to put this in instructable and honestly speaking i did too, but my sister convinced me by telling that not everyone knows how to freeze fruits and we should share our learning. So here you go. This method can be used to freeze any fruit. Hope this helps :)

Step 1: How to Freeze

Cut watermelon pieces and place them on a plate fitted with wax paper/parchment paper/plastic wrap.
Place the plate in the freezer and wait for the pieces to completely freeze.
Take the frozen pieces and place in zip lock bag and put it back into the freezer. Done !!

Next time whenever you need watermelon, just take how many ever pieces you want and place the remaining pieces back in the freezer.